JP2003123820A - Carbon monoxide remover and fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain side reaction due to excessive rise in temperature of a carbon monoxide remover (30) of a fuel cell system (1) and also surely prevent degradation of CO removal performance. SOLUTION: In stead of cooling a catalyst layer (31) of the carbon monoxide remover (30) during reaction, reformed gas is cooled beforehand down to not higher than a given temperature with a heat exchanger (33) for cooling reformed gas to supply to the carbon monoxide remover (30), so that a reacting part of the carbon monoxide remover (30) is restrained from excessively rising in temperature.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a carbon monoxide remover for substantially reducing carbon monoxide concentration in a reformed gas supplied to a fuel cell in a fuel cell system to substantially remove carbon monoxide. And a fuel cell system including the carbon monoxide remover.

[0002]

2. Description of the Related Art In general, a fuel cell system supplies a hydrogen-rich reformed gas produced by reforming a raw material gas such as city gas to a fuel cell to generate hydrogen in the reformed gas and oxygen in the air. It is configured to convert the energy when water is produced by the reaction of to electricity. In this system, a reformer is generally used to generate a hydrogen-rich reformed gas from a raw material gas from which sulfur compounds have been removed in a reforming process before the raw material gas is supplied to a fuel cell.

Here, in a solid polymer fuel cell having a hydrogen electrode and an oxygen electrode which are arranged with an electrolyte made of a solid polymer sandwiched therebetween, carbon monoxide is mixed in a reformed gas used as a fuel. Then, the carbon monoxide poisons the catalyst of the hydrogen electrode of the fuel cell, and the power generation efficiency of the cell decreases.
On the other hand, in the reformer, carbon monoxide is generated along with the reforming reaction of the raw material gas. Therefore, in the system using the polymer electrolyte fuel cell, carbon monoxide is provided on the downstream side of the reformer. A transformer is used to transform carbon dioxide into carbon dioxide.

Further, in this polymer electrolyte fuel cell, in order to obtain sufficient power generation characteristics, it is necessary to reduce the carbon monoxide concentration in the reformed gas to a level of 10 ppm or less, while the above-mentioned transformer is used. It is difficult to achieve this level alone. For this reason, conventionally, after mixing the reformed gas generated in the reformer and the shift converter with air, the mixture should be passed through a carbon monoxide remover including a selective oxidation catalyst that selectively oxidizes carbon monoxide. By this, the remaining carbon monoxide is substantially removed. Specifically, in the carbon monoxide remover, carbon monoxide in the reformed gas is converted into a reaction formula of CO + (1/2) O ₂ → CO ₂ +282.9 KJ / mol ... in the presence of a selective oxidation catalyst. It is removed by the combustion reaction shown.

[0005]

The reaction in the carbon monoxide remover is a reaction with a large heat generation as shown in the above formula, but the reaction temperature is excessive (for example, 200 ° C. or higher) depending on the course of the reaction. ), H ₂ + (1/2) O ₂ → H ₂ O + 241.8KJ / mol… CO + 3H ₂ → CH ₄ + H ₂ O + 205.8KJ / mol… CO ₂ + 4H ₂ → CH ₄ + 2H ₂ O + 164.6KJ / There is a risk that the side reaction as shown in each equation of mol ... Is caused and the hydrogen gas serving as the fuel of the fuel cell is consumed, so that the efficiency is reduced or methane is generated. Also,
On the contrary, if the reaction temperature is too low, the reaction of the above formula becomes difficult to proceed. From the above, it is considered ideal to keep the reaction temperature in the carbon monoxide remover in the temperature range around 150 ° C.

[0006] On the premise of such an idea, various techniques have been conventionally proposed in order to realize the reaction in the above temperature range in the carbon monoxide remover. For example, Japanese Patent Laid-Open No. 2000-203801 discloses a heat-exchangeable catalyst device (carbon monoxide remover) in which a plate or a metal honeycomb is coated with a catalyst layer, and the heat exchange fins carry the catalyst. The configuration is described. In this device, the heat of reaction when converting carbon monoxide into carbon dioxide is recovered by the heat recovery medium via the heat exchange fins to lower the temperature of the reaction section.

However, when the catalyst is cooled during the reaction as described above, a temperature distribution is likely to occur in the catalyst, and it is difficult to maintain a uniform reaction temperature. That is, hot spots and cold spots are generated on the catalyst due to temperature unevenness, and it becomes difficult for a uniform oxidation reaction to occur. For example, when water is caused to flow around the fins as the heat recovery medium, the temperature of the catalyst becomes low in the vicinity of the water, the reaction rate is slow and the CO concentration is not sufficiently reduced, whereas the area away from the water is The temperature becomes high and side reactions occur.

As described above, in the conventional carbon monoxide remover, it is theoretically preferable to maintain the reaction temperature within a predetermined temperature range, but in reality, the reaction range is maintained. It has been extremely difficult to obtain a uniform reaction. The present invention was devised in view of such problems, and an object thereof is to suppress side reactions due to excessive temperature rise and surely prevent performance deterioration in a carbon monoxide remover. It is to be.

[0009]

According to the present invention, the catalyst layer (31) itself is not cooled during the reaction, and the reformed gas is cooled to a predetermined temperature or lower in advance and then the carbon monoxide remover (30) is used. By supplying the carbon monoxide, it is possible to prevent the temperature from excessively rising in the reaction part of the carbon monoxide remover (30).

Specifically, the first to ninth means for solving the problems of the present invention are to remove carbon monoxide in the reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst. It is premised on a carbon monoxide remover (30) that removes by oxidation at.

The carbon monoxide remover (30) according to the first means is a heat insulating layer (32) covering the periphery of the catalyst layer (31) containing the catalyst, and a catalyst in the reformed gas passage. Reformed gas cooling means (3) located upstream of the layer (31) for cooling the reformed gas.
3) and the reformed gas cooling means (33), the catalyst layer (31)
It is characterized in that the reformed gas flowing into is cooled to a temperature at which the outlet temperature of the catalyst layer (31) becomes lower than the side reaction generation temperature. For example, when the side reaction generation temperature is about 200 ° C., the reformed gas is cooled by the reformed gas cooling means (33) to a temperature of about 80 ° C. to 90 ° C. or lower and charged into the catalyst layer (31). Good to do.

In the first solution, the reformed gas flowing into the carbon monoxide remover (30) is supplied to the reformed gas cooling means (3).
After being cooled in 3), it passes through the catalyst layer (31). When the reformed gas passes through the catalyst layer (31), the temperature of the reformed gas rises from the inlet side to the outlet side due to the reaction heat, but the outlet temperature does not rise above the side reaction generation temperature. In addition, the catalyst layer (3
1) is insulated from the surroundings and left to the exothermic reaction so that the temperature rises from the inlet side to the outlet side.
Since (31) is not forcibly cooled, the temperature of the catalyst layer (31) becomes substantially uniform on the plane orthogonal to the flow direction of the reformed gas. Therefore, the occurrence of hot spots and cold spots is prevented.

The second means for solving the problems of the present invention is as follows.
In the above first solution means, a reformed gas cooling means (33)
Is configured to cool the reformed gas flowing into the catalyst layer (31) to a temperature not higher than the reaction start temperature in the catalyst layer (31). For example, when the side reaction generation temperature is about 200 ° C. and the reaction initiation temperature is about 100 ° C., the reformed gas is cooled to about 80 ° C. by the reformed gas cooling means (33).
It may be cooled to a temperature of 90 ° C. or lower.

In the second solution means, the reformed gas is cooled by the reformed gas cooling means (33) to a temperature lower than the reaction start temperature in the catalyst layer (31) and flows into the catalyst layer (31). .
During operation, the temperature of the catalyst layer (31) is rising due to reaction heat,
The reformed gas absorbs this heat and rises in temperature above the reaction start temperature to start the reaction. After that, the temperature of the reformed gas rises to a temperature lower than the side reaction generation temperature and flows out from the catalyst layer (31).

The third means for solving the problems of the present invention is as follows.
In the first or second solving means described above, the catalyst layer (31) is divided at an intermediate portion of the flow path of the reformed gas, and at the divided portion,
It is characterized in that a second reformed gas cooling means (36) is provided.

In the third solution, the reformed gas is cooled to a predetermined temperature on the upstream side of the catalyst layer (31) and then flows into the catalyst layer (31) to rise in temperature, and then the catalyst layer ( In the middle part of 31), it is cooled again by the second reformed gas cooling means (36). Then, after further passing through the catalyst layer (31), it flows out from the catalyst layer (31) at a temperature lower than the side reaction generation temperature.

The fourth means for solving the problems of the present invention is as follows.
In the first, second or third solution means, the reformed gas cooling means (33, 36) is a heat exchanger for recovering the heat of the reformed gas flowing into the catalyst layer (31) into a heat recovery medium. It is characterized by being configured.

Further, the fifth to eighth solving means of the present invention specify the heat recovery medium of the fourth solving means, and the fifth solving means is the fourth solving means. In the above, the reformed gas cooling means (33, 36) is a heat exchanger that uses the fuel cell cooling water as a heat recovery medium from the reformed gas.

The sixth means for solving the problems of the present invention is as follows.
In the fourth solving means, the reformed gas cooling means (33,3
6) is a heat exchanger that uses heat transfer water to which exhaust heat of the fuel cell 10 is given as a heat recovery medium from the reformed gas. This heat transfer water can be used for hot water supply, for example.

The seventh means for solving the problems of the present invention is as follows.
In the fourth solving means, the reformed gas cooling means (33,3
6) is a heat exchanger using air or oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) as a heat recovery medium from the reformed gas.

The eighth means for solving the problems of the present invention is as follows.
In the fourth solving means, the reformed gas cooling means (33,3
6) is a heat exchanger that uses the exhaust gas of the fuel cell (10) as a heat recovery medium from the reformed gas. In this case, it is possible to use either the hydrogen electrode exhaust gas or the oxygen electrode exhaust gas, or to use a mixture thereof.

In the above fourth to eighth means, the reformed gas is the fuel cell cooling water, the heat transfer water, the air or the oxygen which flows through the heat exchanger provided as the reformed gas cooling means (33, 36). It is cooled to a predetermined temperature by a contained gas or a heat recovery medium such as battery exhaust gas, flows into the catalyst layer (31), and flows out from the catalyst layer (31) at a temperature lower than the side reaction generation temperature.

The ninth means for solving the problems of the present invention is as follows.
In any one of the first to eighth solving means, the reformed gas cooling means (33, 36) and the catalyst layer (31) are provided in an integral casing (35). .

[0024] In the ninth solution, the reformed gas flowing into the carbon monoxide remover (30) is an integral casing.
In (35), while being cooled by the reformed gas cooling means (33, 36), carbon monoxide reacts with oxygen and is removed when passing through the catalyst layer (31).

Next, the tenth to nineteenth means for solving the problems of the present invention are to remove carbon monoxide in the reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst. It is premised on a fuel cell system equipped with a carbon monoxide remover (30) for removing by oxidation.

The fuel cell system according to the tenth means corresponds to the first means, and specifically, the carbon monoxide remover (30) includes a catalyst containing the catalyst. A heat insulating layer (32) covering the periphery of the layer (31) and a reformed gas cooling means (33) for cooling the reformed gas positioned upstream of the catalyst layer (31) in the reformed gas channel are provided. The reformed gas cooling means (33) is configured to cool the reformed gas flowing into the catalyst layer (31) to a temperature at which the outlet temperature of the catalyst layer (31) becomes lower than the side reaction generation temperature. It is characterized by being.

The eleventh solving means of the present invention corresponds to the above second solving means. Specifically, in the tenth solving means, the carbon monoxide remover (30 ) Reformed gas cooling means (33) is configured to cool the reformed gas flowing into the catalyst layer (31) to a temperature not higher than the reaction start temperature in the catalyst layer (31). I am trying.

The twelfth solving means of the present invention corresponds to the above-mentioned third solving means. Specifically, in the above-mentioned tenth or eleventh solving means, carbon monoxide is removed. The catalyst layer (31) of the vessel (30) is divided at an intermediate portion of the reformed gas flow path, and the second reformed gas cooling means (36) is provided at the divided portion. .

The thirteenth solving means of the present invention corresponds to the above fourth solving means. Specifically, in the tenth, eleventh or twelfth solving means, Reformed gas cooling means (33, 3) of the carbon oxide remover (30)
6) is configured as a heat exchanger for recovering the heat of the reformed gas flowing into the catalyst layer (31) into the heat recovery medium.

The fourteenth solving means of the present invention corresponds to the above fifth solving means. Specifically, in the above thirteenth solving means, the fuel cell (10) is cooled. The reforming gas cooling means (33, 33) of the carbon monoxide remover (30) is provided with a fuel cell cooling water circuit for circulating the fuel cell cooling water
36) is a heat exchanger that uses the fuel cell cooling water as a heat recovery medium from the reformed gas.

The fifteenth solving means of the present invention corresponds to the sixth solving means. Specifically, in the thirteenth solving means, the exhaust of the fuel cell (10) is eliminated. The reforming gas cooling means (33, 36) of the carbon monoxide remover (30) is provided with a hot water circuit in which the heating medium water to which heat is circulated is used as a heat recovery medium from the reforming gas. It is characterized by being a heat exchanger.

The sixteenth solving means of the present invention corresponds to the seventh solving means. Specifically, in the thirteenth solving means, the carbon monoxide remover (30 ), The reformed gas cooling means (33, 36) is a heat exchanger that uses air or oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) as a heat recovery medium from the reformed gas. I am trying.

The seventeenth solving means of the present invention corresponds to the above eighth solving means. Specifically, in the thirteenth solving means, the carbon monoxide remover (30 The reformed gas cooling means (33, 36) is a heat exchanger that uses the exhaust gas of the fuel cell (10) as a heat recovery medium from the reformed gas. In this case, it is possible to use either the hydrogen electrode exhaust gas or the oxygen electrode exhaust gas, or to use a mixture thereof.

The eighteenth solving means of the present invention corresponds to the above ninth solving means. Specifically, in any one of the above tenth to seventeenth solving means, The carbon monoxide remover (30) is a reformed gas cooling means (33,
It is characterized that the catalyst layer (31) and the catalyst layer (31) are provided in an integral casing (35).

Further, a nineteenth solution means of the present invention is the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) according to any one of the above tenth to seventeenth solution means. )
However, it is characterized in that the reformed gas flowing into the catalyst layer (31) is started to be cooled after a lapse of a predetermined time from the start of the system.

In the seventeenth solution, since the high temperature reformed gas from the transformer (22) is not cooled at the time of starting the system, after a lapse of a predetermined time from the start, the catalyst layer (31)
Rises above the reaction start temperature to start the reaction. Further, once the reaction starts, the reformed gas is cooled by the reformed gas cooling means (33) and then heated to the reaction starting temperature or higher by the reaction heat in the catalyst layer (31) to continue the reaction. At this time, the outlet temperature does not rise above the side reaction generation temperature.

[0037]

EFFECTS OF THE INVENTION According to the first and tenth means for solving the problems, the periphery of the catalyst layer (31) is covered with the heat insulation layer (32), and the reformed gas flowing into the catalyst layer (31) is reformed gas. The cooling means (33) is used for cooling. Therefore, although the temperature rises from the inlet side to the outlet side of the catalyst layer (31), the temperature becomes substantially uniform on the surface orthogonal to the flow direction of the reformed gas. Therefore, since it is possible to prevent the occurrence of hot spots and cold spots, side reactions occur at the hot spots, and C at the cold spots.
It is possible to prevent a problem in which the O concentration is not sufficiently reduced. That is, in the conventional structure in which the catalyst layer (31) is made to have a uniform temperature throughout, it is extremely difficult to suppress the side reaction and prevent the performance deterioration, while the catalyst layer (3
By allowing the temperature gradient from the inlet side to the outlet side in the heat-insulated state of 1), suppression of side reactions and prevention of performance deterioration can be realized.

As described above, the carbon monoxide remover (3
In (0), the carbon monoxide concentration can be substantially removed by sufficiently reducing the carbon monoxide concentration, so that the poisoning of the catalyst in the fuel cell (10) can be reliably prevented.

According to the second and eleventh solving means, the reformed gas is cooled to a temperature lower than the reaction start temperature in the catalyst layer (31), so that the reformed gas undergoes a side reaction. It is possible to effectively prevent the temperature above the generation temperature from rising,
Moreover, during operation, the reformed gas rises to a temperature higher than the reaction start temperature due to the heat of reaction, so that it is possible to prevent the carbon monoxide removal performance from decreasing.

Further, according to the third and twelfth solving means, the second reformed gas cooling means (3
Since 6) is provided, it is possible to more effectively prevent the reformed gas from rising to a temperature higher than the side reaction generation temperature. For this reason, in the case of a system in which a reformed gas having a relatively high carbon monoxide concentration is introduced into the carbon monoxide remover (30), the outlet temperature is likely to rise above the side reaction generation temperature, while it is excessive. The temperature rise can be prevented more reliably.

According to the fourth to eighth solving means and the thirteenth to seventeenth solving means, the heat recovery of the fuel cell cooling water, the heat transfer water, the air or oxygen-containing gas, the cell exhaust gas or the like is performed. By using it as a medium, it is possible to prevent the occurrence of side reactions while preventing the performance from deteriorating, and also to prevent the structure from becoming complicated.

Further, according to the ninth and eighteenth solving means, since the reformed gas cooling means (33, 36) and the catalyst layer (31) are provided in the integral casing (35), The structure of the carbon monoxide remover (30) can be simplified.

Further, according to the nineteenth solving means, the reformed gas is not cooled at the time of starting, but the cooling is started after a predetermined time has passed from the starting. Therefore, the means for heating the reformed gas at the time of starting. It is not necessary to provide such as, and it is possible to prevent the configuration from becoming complicated. Further, similar to each of the above solving means, there is no side reaction due to excessive temperature rise, and conversely, the temperature is not lowered and the performance is not deteriorated, and the system can be continuously operated in an appropriate state. it can.

[0044]

Embodiment 1 of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a circuit block diagram of the fuel cell system (1) according to the first embodiment. As shown,
This fuel cell system (1) consists of a fuel cell (10) and a reformer.
(20), a cooling water circuit (40) and a hot water storage circuit (50).

The fuel cell (10) is of a solid polymer electrolyte type. In this fuel cell (10), a unit cell is constituted by forming electrodes by dispersing catalyst particles on both sides of an electrolyte membrane made of, for example, a fluorine-based polymer film. One of the electrodes on the surface of the electrolyte membrane serves as a hydrogen electrode (anode) and the other serves as an oxygen electrode (cathode). The fuel cell (10) constitutes a stack (assembled cell) in which unit cells are stacked via bipolar plates. The structure of the fuel cell (10) described above is omitted in FIG.

In the above fuel cell (10), the oxygen electrode side gas passage (11) is formed by the bipolar plate and the oxygen electrode of the electrolyte membrane, and the hydrogen electrode side gas passage (12) is formed by the bipolar plate and the hydrogen electrode of the electrolyte membrane. ) Is formed. Oxygen electrode side gas passage
The air passage (2) is connected to the inlet (11) through the air supply pipe (13) and the oxygen electrode exhaust pipe (14) is connected to the outlet. On the other hand, the reforming gas passage (3) is connected to the hydrogen electrode side gas passage (12) through the hydrogen supply pipe (15) on the inlet side, and the hydrogen electrode exhaust pipe (16) is on the outlet side. It is connected.

The oxygen electrode exhaust pipe (14) and the hydrogen electrode exhaust pipe (16) are
It is connected to the fuel cell exhaust pipe (17). Fuel cell exhaust pipe
The (17) is connected to the combustor (18) and the cell exhaust gas cooling heat exchanger (19), and is configured to cool and exhaust the exhaust gas of the fuel cell after combustion. The combustor (18) burns hydrogen (H ₂ ) remaining in the hydrogen electrode exhaust gas by using oxygen (O ₂ ) remaining in the oxygen electrode exhaust gas. The exhaust gas cooling heat exchanger (19) collects the heat quantity of the combustion gas and stores hot water.

The above reformer (20) is provided on the reformed gas passage (3), and the reformer (2
1) and a transformer (22), and a carbon monoxide remover (30). The reformer (21) is connected to a supply source of city gas which is a raw material gas. A desulfurizer (not shown) that removes sulfur compound components from the city gas is connected between the reformer (21) and the city gas supply source as needed.

The reformer (21) causes, for example, a desulfurized city gas and water (steam) supplied from a tank (not shown) to undergo a reforming reaction while being heated by a burner, and mainly carbon dioxide and hydrogen. A reformed gas containing is generated. The reformed gas generated in the reformer (21) also contains carbon monoxide, and the shift converter (22) shifts the carbon monoxide to carbon dioxide.

Since the carbon monoxide remover (30) reduces the power generation efficiency of the fuel cell system (1) when carbon monoxide remains in the reformed gas, the carbon monoxide is removed from the reformed gas. It is configured to oxidize and remove in the presence of a selective oxidation catalyst. This carbon monoxide remover (30) includes a catalyst layer (31) containing the above catalyst (in the figure, a block of this catalyst layer indicates "carbon monoxide remover") and at least this catalyst layer (31). A heat insulating layer (32) (see FIG. 2) covering the periphery of the catalyst layer (31), and a reformed gas cooling heat exchanger (33) as a reformed gas cooling means located upstream of the catalyst layer (31). ing. This reformed gas cooling heat exchanger (33) is a catalyst layer of the carbon monoxide remover (30).
The reformed gas flowing into (31) is configured to be cooled to a temperature at which the outlet temperature of the catalyst layer (31) becomes lower than the side reaction generation temperature.

On the downstream side of the catalyst layer (31) of the carbon monoxide remover (30), the reformed gas flowing out from the catalyst layer (31) is fed to the fuel cell (1).
An auxiliary heat exchanger (34) is provided for cooling to the input temperature to 0). Regarding the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34), the provision of the reformed gas cooling heat exchanger (33) is one of the features of the present invention, while the auxiliary heat The exchanger (34) is conventionally used.

The air passage (2) is branched at two locations on the upstream side of the fuel cell (10) so that the catalyst layer (on the upstream side of the reformer (21) and the carbon monoxide remover (30) ( The upstream side of 31) is connected to the reformed gas passage (3).

The cooling water circuit (40) is a closed circuit filled with cell cooling water, and by circulating the cell cooling water in this cooling water circuit (40), the fuel cell (10) can be operated in a predetermined manner. Maintained at operating temperature. This cooling water circuit (40) includes a battery cooling water tank (41), a fuel cell (10), a reformed gas cooling heat exchanger (33).
And auxiliary heat exchanger (34), battery exhaust gas cooling heat exchanger (19),
And the hot water heat exchanger (51) are sequentially connected. A cooling water pump (not shown) is provided in this circuit.

The hot water heat exchanger (51) has a hot water storage tank (52).
The hot water heat exchanger (51) and the hot water storage tank (52) constitute the hot water storage circuit (50). This hot water storage circuit (50) includes a reformed gas cooling heat exchanger (33) and an auxiliary heat exchanger (3
4) and the heat of the battery cooling water heated in the battery exhaust gas cooling heat exchanger (19) are stored in the hot water heat exchanger (51) in the hot water storage circuit.
The hot water is supplied to the hot water (heat medium water) of (50), and a hot water pump (not shown) is provided in the circuit. The hot water in the hot water storage tank (52) is supplied to hot water as needed.

Next, the carbon monoxide remover (30) will be specifically described. FIG. 2 is a perspective view conceptually showing the structure of the carbon monoxide remover (30), and FIGS. 3 and 4 are views showing an example of the specific structure. 3, (a) is a left side view of the carbon monoxide remover (31), (b) is a front view, (c) is a right side view, (d) is a plan view, and FIG. 4 is FIG. (B)
FIG. 4 is a sectional view taken along line IV-IV.

In the figure, a carbon monoxide remover (30) includes a catalyst layer (31) containing the above-mentioned carbon monoxide selective oxidation catalyst and a reforming gas cooling heat exchange located upstream of the catalyst layer (31). Bowl (33)
And the auxiliary heat exchanger (34) located on the downstream side of the catalyst layer (31) in a single casing (35). Further, in the casing (35), the catalyst layer (31) and both heat exchangers (33, 34)
A heat insulating layer (32) is provided to cover the whole. The heat insulating layer 32 is omitted in FIG. 3 for convenience. The heat insulating layer (32) only needs to cover at least the periphery of the catalyst layer (31) and does not necessarily have to be provided around both heat exchangers (33, 34).

Each of the heat exchangers (33, 34) is a plate fin coil type heat exchanger as shown in FIG. 4, and the fins (33a, 34a) of each heat exchanger (33, 34) are vertically It is arranged in two stages. The pipes (42) of the cooling water circuit (40) are connected to these heat exchangers (33, 34). Specifically, the lower side of the auxiliary heat exchanger (34) and the lower side of the reformed gas cooling heat exchanger (33) are connected to each other by a cooling water pipe (42) to remove the carbon monoxide remover (30). In the cooling water inlet side, the upper side of the auxiliary heat exchanger (34) and the upper side of the reformed gas cooling heat exchanger (33) are connected to each other by a cooling water pipe (42). It is configured on the exit side.

As described above, the reformed gas cooling heat exchanger (33) located on the upstream side of the catalyst layer (31) transfers the heat of the reformed gas flowing into the catalyst layer (31) to the heat recovery medium ( In the case of the first embodiment, a reformed gas cooling means for cooling the reformed gas to a predetermined temperature by collecting it in the battery cooling water) is configured. Specifically,
This heat exchanger (33) cools the reformed gas that flows into the catalyst layer (31) whose periphery is insulated to, for example, 90 ° C., so that the temperature at the outlet side of the catalyst layer (31) that becomes the highest becomes The temperature is set to be lower than the side reaction generation temperature (for example, 200 ° C.).
Further, in this Embodiment 1, the reaction start temperature in the catalyst layer (31) is, for example, 100 ° C. That is, the reformed gas cooling heat exchanger (33) cools the reformed gas flowing into the catalyst layer (31) to a temperature equal to or lower than the reaction start temperature in the catalyst layer (31).

-Operational Behavior- Next, the operation of the fuel cell system (1) during power generation will be described.

First, when a desulfurizer is provided in the reformed gas passage (3), the sulfur compound component in the raw material gas is removed in the desulfurizer, the gas is mixed with air, and the reformer (2
Sent to 1). In the reformer (21), the raw material gas and the steam supplied from a tank (not shown) are subjected to a steam reforming reaction while being heated by a burner to generate a reformed gas containing mainly carbon dioxide and hydrogen.

Although the reformed gas also contains carbon monoxide as described above, the carbon monoxide component in the gas is reduced in the shift converter (22). The composition of the reformed gas exiting the transformer (22), in the present embodiment 1, for _{example, CH 4: 0.7% H 2} O: 26.03% H 2: 35.8% CO: 0. _{52% CO 2: 12.39% N} 2: becomes 24.57%, carbon monoxide, a concentration 0.32% were lowered. This reformed gas further flows into the carbon monoxide remover (30), and carbon monoxide is removed by oxidation. At this time,
Air is mixed with the reformed gas, and O ₂ / CO at that time is mixed.
(Oxygen and carbon monoxide volume ratio) is generally about 2.
It was about 0-2.5, but about 1.0-1.5
Is set to. That is, in the present embodiment, the amount of oxygen input to the carbon monoxide remover (30) is smaller than in the conventional case.

The reformed gas leaving the carbon monoxide remover (30) is
The carbon monoxide concentration becomes lower than the target value of 10 ppm and is supplied to the fuel cell (10). In the fuel cell (10), hydrogen in the reformed gas sent from the carbon monoxide remover (30) and oxygen in the air sent from the blower (not shown) or the like through the air supply pipe (13) Electricity is generated by binding and converting the ions generated at that time into charges of the cathode and the anode.

The reformed gas flowing into the carbon monoxide remover (30) is supplied to the fuel cell in the reformed gas cooling heat exchanger (33).
It is cooled to a temperature of about 80 ° C to 90 ° C by exchanging heat with the battery cooling water (about 75 ° C) after cooling in (10). This temperature is
The temperature is lower than the reaction initiation temperature (about 100 ° C.) in the catalyst layer (31), and by setting such a temperature, the outlet temperature of the catalyst layer (31) becomes lower than the side reaction generation temperature. ing.

When the fuel cell system (1) is started,
The reformed gas is not cooled by the reformed gas cooling heat exchanger (33), and the reformed gas is supplied to the carbon monoxide remover (30) at a high temperature flowing out from the shift converter (22). Therefore, the temperature of the catalyst layer (31) becomes higher than the reaction start temperature after a lapse of a predetermined time from the start, and the reaction continues.

As described above, during the operation of the fuel cell system (1), the temperature of the catalyst layer (31) is higher than the above reaction initiation temperature due to the heat of reaction, and the reformed gas cooling heat exchanger (33)
When the reformed gas cooled in (3) flows into the catalyst layer (31) of the carbon monoxide remover (30), the temperature of the reformed gas rises due to the heat of reaction and the reaction is started. Then, the temperature of the reformed gas gradually rises from the inlet side to the outlet side of the catalyst layer (31), and the temperature of the reformed gas from the catalyst layer (31) is lower than the temperature (200 ° C.) at which a side reaction occurs. leak.

As described above, during the operation of the system, the reformed gas flowing into the catalyst layer (31) is cooled without cooling the catalyst layer (31) while the catalyst layer (31) is insulated. By cooling in advance, a substantially uniform temperature gradient is generated in the catalyst layer (31) from the inlet side to the outlet side. On the other hand, the catalyst layer (3
In 1), the temperature becomes almost uniform in the plane direction orthogonal to the flow of the reformed gas, and cold spots and hot spots do not occur. Therefore, as a whole, a stable oxidation reaction occurs and an excessive rise in temperature is suppressed, so that no side reaction occurs in the carbon monoxide remover (30) and the performance does not deteriorate.

Further, the reformed gas flowing out from the catalyst layer (31) is cooled to a temperature (about 80 ° C.) introduced into the fuel cell (10) in the auxiliary cooling heat exchanger (34), and the fuel cell (10) is cooled. ) Into the hydrogen electrode side gas passage (12). The hydrogen electrode exhaust gas and the oxygen electrode exhaust gas of the fuel cell merge in the fuel cell exhaust pipe (17) and are burned in the combustor (18), and then the battery exhaust gas cooling heat exchanger (19)
It is cooled by exchanging heat with the battery cooling water and exhausted.

On the other hand, in the cooling water circuit (40), the battery cooling water flowing out from the reformed gas cooling heat exchanger (33) is heated by the battery exhaust gas cooling heat exchanger (19), and further heated by the hot water heat exchanger. After being cooled in (51), it returns to the battery cooling water tank (41). The cooling water returned to the battery cooling water tank (41) flows to the reforming gas cooling heat exchanger (33) and the auxiliary heat exchanger (34) after cooling the fuel cell (10), and reforms again. Cool the gas.

Further, in the hot water heat exchanger (51), the battery cooling water and the hot water for hot water exchange heat to heat the hot water for hot water supply. The hot water for hot water supply is stored in the hot water storage tank (52) and used for hot water supply as needed.

-Effects of First Embodiment- According to the first embodiment, the heat insulating layer (32) is provided around the catalyst layer (31).
And the reformed gas flowing into the catalyst layer (31) is cooled by the reformed gas cooling heat exchanger (33).
Although the temperature rises from the inlet side to the outlet side in 1), the temperature is made to be almost uniform in the plane direction orthogonal to the flow direction of the reformed gas, so hot spots and cold spots are not generated. Can be prevented.
Therefore, it is possible to prevent a side reaction from occurring in the hot spot and a problem in which the CO concentration is not sufficiently reduced in the cold spot.

That is, while it is difficult to suppress the side reaction and prevent the performance from being lowered in the constitution in which the temperature of the catalyst layer (31) is made uniform throughout, the catalyst layer (31) is thermally insulated. In such a state, it is possible to realize the suppression of the side reaction and the prevention of the performance deterioration by allowing the temperature gradient to be substantially uniform from the inlet side to the outlet side.

Further, conventionally, it was necessary to set O ₂ / CO (volume ratio of oxygen and carbon monoxide) to about 2.0 to 2.5, whereas according to this embodiment, the reaction The target value (10 ppm) can be achieved even if O ₂ / CO is set to about 1.0 to 1.5 for stability and the O ₂ input amount is reduced. As a result, the hydrogen yield is increased and the efficiency is improved.

The temperature of the reformed gas (about 80 ° C. to 90 ° C.) lower than the reaction start temperature (about 100 ° C.) in the catalyst layer (31).
Since it is cooled to (° C.), the reformed gas can be effectively prevented from rising to a temperature higher than the side reaction generation temperature (200 ° C.). Moreover, even with such a temperature setting, the reformed gas rises to a temperature higher than the reaction start temperature due to the reaction heat during the operation, so that the carbon monoxide removing performance can be prevented from being deteriorated.

Further, according to the present embodiment, in the carbon monoxide remover (30), the carbon monoxide concentration can be sufficiently reduced and the carbon monoxide can be substantially removed while suppressing side reactions. It is possible to reliably prevent the poisoning of the catalyst in (10).

Furthermore, in the first embodiment, since the complicated structure for inserting the fins into the catalyst layer to cool the catalyst and the complicated structure for circulating water to cool the catalyst layer are not necessary, the structure is Can be simplified.

-Modification of Embodiment 1- (Modification 1) FIG. 5 is a perspective view conceptually showing the structure of a modification of the carbon monoxide remover (30). In this carbon monoxide remover (30), the catalyst layer (31) is divided at the middle portion of the flow path of the reformed gas, and the middle portion between the catalyst layer (31a) at the front stage and the catalyst layer (31b) at the rear stage, A second reformed gas cooling heat exchanger (36) is provided as a reformed gas cooling means. In other words, the carbon monoxide remover (30) has the catalyst layer (31) described in the first embodiment.
In addition to the reformed gas cooling heat exchanger (33) on the upstream side of the catalyst and the auxiliary heat exchanger (34) on the downstream side of the catalyst layer (31), the second heat exchanger is located in the middle part of the catalyst layer (31). The reformed gas cooling heat exchanger (36) is provided.

Battery cooling water flows through each heat exchanger (33, 34, 36) as in the first embodiment. Then, the battery cooling water and the reformed gas exchange heat with each other to cool the reformed gas.

In addition, in the carbon monoxide remover (30), the catalyst layer (31
It is configured so that air is blown into b). In other words, the oxygen that flows into the carbon monoxide remover (30) together with the reformed gas is consumed by the reaction in the catalyst layer (31a) in the front stage, so oxygen is supplied to the reaction in the catalyst layer (31b) in the rear stage. I am trying to do it.

In this modification, the reformed gas is used as the catalyst layer (31).
After cooling to a specified temperature on the upstream side of the
After flowing into (31a) and rising in temperature, both catalyst layers (31a, 31b)
By being cooled again by the second reformed gas cooling means (36) in the intermediate part of
The temperature can be set so as to flow out from the catalyst layer at a temperature lower than the side reaction generation temperature. Therefore, the carbon monoxide remover (30), when the reformed gas supplied from the shift converter (22) contains, for example, more than 0.6% carbon monoxide,
It is possible to effectively prevent the reformed gas from rising to a temperature higher than the side reaction generation temperature. That is, in the case of a system in which a carbon monoxide remover (30) treats a reformed gas having a relatively high CO gas concentration containing more than 0.6% of carbon monoxide,
Since the amount of oxygen input also increases, the outlet temperature tends to rise above the side reaction generation temperature, but an excessive temperature rise can be reliably prevented.

On the other hand, the first embodiment is suitable for treating the reformed gas containing carbon monoxide of about 0.4% to 0.6%, and has a complicated structure as compared with this modification. Can be prevented.

(Modification 2) The reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34) are the same as the cooling water circuit (4) in FIGS. 1 and 3.
In (0), they are connected in parallel with each other,
These heat exchangers (33, 34) may be connected in series.

FIG. 6 shows an example in which both heat exchangers (33, 34) are connected in series. Specifically, the upper side of the auxiliary heat exchanger (34) and the lower side of the reformed gas cooling heat exchanger (33) are connected by an intermediate pipe, while the lower side of the auxiliary heat exchanger (34) and the reformer are connected. The upper stages of the gas cooling heat exchangers (33) are connected to the cooling water pipes (42), respectively, and are configured as the inlet side and the outlet side of the cooling water in the carbon monoxide remover (30).

Even in this case, the same effect as that of the carbon monoxide remover (30) in FIG. 3 can be obtained.

[0085]

Embodiment 2 In Embodiment 2 of the present invention, the hot water for storage (heat medium water) in the hot water storage circuit (50) to which the exhaust heat of the fuel cell is given is supplied to the reformed gas cooling heat exchanger (33). It is used as a heat recovery medium from the reformed gas.

The second embodiment is different from the fuel cell system (1) of the first embodiment in that a cooling water circuit (40) and a hot water storage circuit (50) are provided.
The configuration of is different. In this Embodiment 2, the cooling water circuit
As shown in FIG. 7, the (40) is configured as a closed circuit in which the battery cooling water tank (41), the fuel cell (10) and the hot water heat exchanger (51) are sequentially connected. The cooling water circuit (40) is provided with a cooling water pump (not shown).

The hot water storage circuit (50) is provided in the hot water storage tank (52).
A hot water heat exchanger (51), a reformed gas cooling heat exchanger (33) and an auxiliary heat exchanger (34), and a battery exhaust gas cooling heat exchanger (19), which are connected in sequence to form a closed circuit. Has been done. A hot water pump (not shown) is provided in the hot water storage circuit (50).

In this fuel cell system (1), a cooling water circuit (40) and a hot water storage circuit such as a reformer (21), a transformer (22), a carbon monoxide remover (30) and a fuel cell (10). The parts other than (50) are configured similarly to the first embodiment.

In the second embodiment, the hot water storage tank (52)
The hot water for storage in the hot water heat exchanger (51) is about 7
Heat to 0 ° C. Then, the stored hot water flows through the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34), so that the reformed gas flowing through the carbon monoxide remover (30) is transferred to the catalyst layer (3).
The cooling is performed on the upstream side and the downstream side of 1) as in the first embodiment.
The hot water for heating stored when the reformed gas is cooled is further heated by exchanging heat with the combustion gas in the battery exhaust gas cooling heat exchanger (19) and returned to the hot water storage tank (52). Hot water storage tank
The hot water for storage in (52) is set to be stored at a temperature of about 85 ° C., although the temperature of the hot water slightly changes due to water supply.

Also in the case of the second embodiment, the catalyst layer (31) of the carbon monoxide remover (30) is not cooled, but the reformed gas is cooled and introduced into the catalyst layer (31). It is possible to prevent hot spots and cold spots from occurring in (31). Therefore, while suppressing the occurrence of side reactions, it is possible to prevent a decrease in carbon monoxide removal performance, and
The poisoning of the catalyst in 0) can be surely prevented.

[0091]

Third Embodiment In the third embodiment of the present invention, the air or oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) is supplied from the reformed gas in the reformed gas cooling heat exchanger (33). It is intended to be used as a heat recovery medium of.

The third embodiment is different from the fuel cell system (1) of the first and second embodiments in that the air passage (2) and the cooling water circuit (40) and the hot water storage circuit (50) are different in configuration. It was done. That is, as shown in FIG. 8, the air passage (2) is
After supplying air to the reformed gas cooling heat exchanger (33) and auxiliary exchanger (34) as a heat recovery medium from the reformed gas, the fuel cell
While flowing in the oxygen electrode side gas passageway (11) of (10), the air passing through the reformed gas cooling heat exchanger (33) is mixed with the raw material gas on the upstream side of the reformer (21) to form the reformed gas. It is configured to flow into the passage (3). In this way, both the air entering the reformer (21) and the air entering the fuel cell (10) are supplied to the reformed gas cooling heat exchanger (33).
Flow into the heat exchanger (33) to maximize the flow rate of air in the heat exchanger (33) so that sufficient cooling performance for the reformed gas can be obtained.

Further, the cooling water circuit (40) is constructed as a closed circuit in which the battery cooling water tank (41), the hot water heat exchanger (51) and the fuel cell (10) are sequentially connected, and this circuit is shown in the drawing. Not equipped with a cooling water pump.

Further, the hot water storage circuit (50) includes a hot water storage tank (52).
And a hot water heat exchanger (51) and a battery exhaust gas cooling heat exchanger (19)
And are connected in order to form a closed circuit. A hot water pump (not shown) is provided in the hot water storage circuit (50).

In the fuel cell system (1), the other parts are constructed in the same manner as in the first and second embodiments.

In the third embodiment, the reformed gas flowing out of the transformer (22) is cooled by exchanging heat with the air from the air passage (2) in the reformed gas cooling heat exchanger (33) ( About 80 ° C to 90 ° C), the catalyst layer (31) of the carbon monoxide remover (30)
Flow into. The reformed gas is heated to a temperature slightly lower than the temperature (about 200 ° C.) at which side reactions occur when passing through the catalyst layer (31), and flows out from the catalyst layer (31). The reformed gas is cooled again by the auxiliary heat exchanger (34) (about 80 ° C.) and is fed into the fuel cell (10). On the other hand, part of the air flowing through the air passage (2) is on the oxygen electrode side of the fuel cell (10) after the reformed gas is partially cooled by the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34). The gas is supplied to the gas passageway (11), and the rest is mixed with the raw material gas and supplied to the reformer (21).

The cell cooling water exchanges heat with the hot water for storage in the hot water heat exchanger (51) and further flows through the fuel cell (10) to cool the fuel cell. The cell cooling water that has cooled the fuel cell (10) returns to the cell cooling water tank (41) and repeats the above circulation.

Further, the hot water for storing hot water stored in the hot water storage tank (52) is circulated in the hot water storage circuit (50) when the hot water heat exchanger (5
After exchanging heat with the battery cooling water in 1), it is heated by exchanging heat with the combustion gas in the battery exhaust gas cooling heat exchanger (19). The heated hot water is returned to the hot water storage tank (52) and the above circulation is repeated.

Also in the case of the third embodiment, the catalyst layer (31) of the carbon monoxide remover (30) is not cooled, but the reformed gas is cooled and introduced into the catalyst layer (31). It is possible to prevent hot spots and cold spots from occurring in (31). Therefore, while suppressing the occurrence of side reactions, it is possible to prevent a decrease in carbon monoxide removal performance, and
The poisoning of the catalyst in 0) can be surely prevented.

[0100]

Fourth Embodiment of the Invention In a fourth embodiment of the present invention, the exhaust gas of the fuel cell (10) is used as a heat recovery medium from the reformed gas in the reformed gas cooling heat exchanger (33). Is.

The fourth embodiment is different from the fuel cell system (1) of the third embodiment in that the air passage (2) and the fuel cell exhaust pipe (17) have different structures. That is,
As shown in FIG. 9, the air passage (2) supplies air to the oxygen-electrode-side gas passage (11) of the fuel cell (10) as in Embodiments 1 and 2, while modifying a part of the air. It is configured to supply to the catalyst layer (31) of the pouch (21) and the carbon monoxide remover (30). Further, the fuel cell exhaust pipe (17) is branched into two and connected to the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34), and then merges to form a combustor (18) and Battery exhaust gas cooling heat exchanger
It is connected to (19).

The other parts such as the cooling water circuit (40) and the hot water storage circuit (50) are constructed in the same manner as in the third embodiment.

In the fourth embodiment, the reformed gas flowing out of the transformer (22) is cooled by exchanging heat with the fuel cell exhaust gas in the reformed gas cooling heat exchanger (33) (about 80 ° C.
90 ° C.) and flows into the catalyst layer (31) of the carbon monoxide remover (30). The reformed gas is heated to a temperature slightly lower than the temperature (about 200 ° C.) at which side reactions occur when passing through the catalyst layer (31), and flows out from the catalyst layer (31). The reformed gas is cooled again (about 80 ° C) by the auxiliary heat exchanger (34), and the fuel cell (1
It is thrown into 0). On the other hand, the air flowing through the air passage (2) is
Part is supplied to the reformer (21) and part is supplied to the carbon monoxide remover
It is supplied to the catalyst layer (31) of (30) and the rest is supplied to the oxygen electrode side gas passage (11) of the fuel cell (10).

When the fuel cell exhaust gas flows through the fuel cell exhaust pipe (17), it is cooled by air, for example, by a fan (not shown) to a temperature of about 80.degree. Then, the reformed gas flowing through the carbon monoxide remover (30) is cooled before and after the catalyst layer (31) by the thus cooled fuel cell exhaust gas. The fuel cell exhaust gas may be cooled to a predetermined temperature by simply exchanging heat with the cell cooling water or the hot water for storing hot water, instead of being simply cooled by air cooling.

Also in the case of the fourth embodiment, the catalyst layer (31) of the carbon monoxide remover (30) is not cooled, but the reformed gas is cooled and introduced into the catalyst layer (31). It is possible to prevent hot spots and cold spots from occurring in (31). Therefore, while suppressing the occurrence of side reactions, it is possible to prevent a decrease in carbon monoxide removal performance, and
The poisoning of the catalyst in 0) can be surely prevented.

[0106]

Other Embodiments of the Invention The present invention may have the following configurations in the above embodiments.

For example, in each of the above embodiments, the reformed gas cooling heat exchanger (33), which is the reformed gas cooling means, recovers heat from the fuel cell cooling water, hot water, air or oxygen-containing gas, or cell exhaust gas. Although the reformed gas is cooled to a predetermined temperature as a medium, other heat recovery medium may be used.

Further, the reformed gas cooling means (33) is not limited to the heat exchanger as long as it can cool the reformed gas to a predetermined temperature, and other cooling elements such as a Peltier effect element are used. May be.

Further, in the second to fourth embodiments, the catalyst layer (31) is divided into two as in the modification of the first embodiment, and the second reforming gas cooling heat as the reforming gas cooling means is provided therebetween. A exchanger may be provided.

Further, in the above embodiment, the catalyst layer (31) of the carbon monoxide remover (30) and the reformed gas cooling heat exchanger (33) are integrally formed, but they are not necessarily integrated. Good.
Further, in the above embodiment, the auxiliary heat exchanger (34) also has a catalyst layer (3
Although it is integrated with 1), the auxiliary heat exchanger (34) does not have to be integrated with the catalyst layer (31).

Further, in the above embodiment, the steam reforming method is taken as an example of the reforming method, but the reforming method may be other than the steam reforming method (for example, partial oxidation reforming method) and is not particularly limited. Not a thing.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a fuel cell system according to a first embodiment of the present invention.

FIG. 2 is a perspective view conceptually showing the structure of a carbon monoxide remover in the fuel cell system of FIG.

3 is an external view showing an example of a specific configuration of the carbon monoxide remover of FIG. 2, (a) is a left side view of the carbon monoxide remover (31), (b) is a front view, (c). ) Is a right side view, and (d) is a plan view.

FIG. 4 is a sectional view taken along line IV-IV of FIG.

5 is a perspective view showing a modified example of the carbon monoxide remover of FIG.

6 is an external view showing a modified example of the carbon monoxide remover of FIG. 3, (a) is a left side view of the carbon monoxide remover (31),
(B) is a front view, (c) is a right side view, and (d) is a plan view.

FIG. 7 is a circuit block diagram of a fuel cell system according to a second embodiment of the present invention.

FIG. 8 is a circuit block diagram of a fuel cell system according to Embodiment 3 of the present invention.

FIG. 9 is a circuit block diagram of a fuel cell system according to Embodiment 4 of the present invention.

[Explanation of symbols]

(1) Fuel cell system (10) Fuel cell (20) Reformer (21) Reformer (22) Transformer (30) Carbon monoxide remover (31) Catalyst layer (32) Thermal insulation layer (33) Modified Quality gas cooling heat exchanger (reformed gas cooling means) (34) Auxiliary heat exchanger (36) Second reformed gas cooling heat exchanger (second reformed gas cooling means) (40) Cooling water circuit ( 50) Hot water storage circuit

Continued front page    (72) Inventor Eisaku Okubo             1304 Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries             Sakai Plant Kanaoka Factory F-term (reference) 4G040 EA03 EA06 EB12 EB31 EB44                 5H026 AA06                 5H027 AA06 BA08 BC06

Claims (19)

[Claims] 1. A carbon monoxide remover for oxidizing and removing carbon monoxide in a reformed gas supplied to a fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst, which comprises the catalyst. A heat insulating layer (32) covering the periphery of the catalyst layer (31),
The reforming gas cooling means (33) is provided upstream of the catalyst layer (31) to cool the reforming gas, and the reforming gas cooling means (33) is a reforming gas flowing into the catalyst layer (31). A carbon monoxide remover characterized in that the gas is cooled to a temperature at which an outlet temperature of the catalyst layer (31) becomes lower than a side reaction generation temperature. 2. The reformed gas cooling means (33) is configured to cool the reformed gas flowing into the catalyst layer (31) to a temperature not higher than the reaction start temperature in the catalyst layer (31). The carbon monoxide remover according to claim 1, wherein: 3. A catalyst layer (31) is divided at an intermediate portion of a reformed gas passage, and a second reformed gas cooling means (3) is provided at the divided portion.
6) is provided, Claim 1 or 2 characterized by the above-mentioned.
The described carbon monoxide remover. 4. The reformed gas cooling means (33, 36) comprises a catalyst layer (3
The carbon monoxide remover according to claim 1, wherein the carbon monoxide remover is configured as a heat exchanger for recovering the heat of the reformed gas flowing into (1) into a heat recovery medium. 5. The carbon monoxide according to claim 4, wherein the reformed gas cooling means (33, 36) is a heat exchanger using the fuel cell cooling water as a heat recovery medium from the reformed gas. Remover. 6. The reformed gas cooling means (33, 36) is a fuel cell.
5. The carbon monoxide remover according to claim 4, wherein the heat exchanger uses heat transfer water to which exhaust heat of (10) is given as a heat recovery medium from the reformed gas. 7. The reformed gas cooling means (33, 36) is a fuel cell.
5. The carbon monoxide remover according to claim 4, which is a heat exchanger using air or an oxygen-containing gas supplied to the oxygen electrode of (10) as a heat recovery medium from the reformed gas. 8. The reformed gas cooling means (33, 36) is a fuel cell.
The carbon monoxide remover according to claim 4, which is a heat exchanger using the exhaust gas of (10) as a heat recovery medium from the reformed gas. 9. A reformed gas cooling means (33, 36) and a catalyst layer (31)
9. The carbon monoxide remover according to claim 1, wherein and are provided in an integral casing (35). 10. A fuel cell provided with a carbon monoxide remover (30) for oxidizing and removing carbon monoxide in a reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst. In the system, the carbon monoxide remover (30) comprises a catalyst layer (3
1) is provided with a heat insulating layer (32) covering the periphery and a reformed gas cooling means (33) located upstream of the catalyst layer (31) to cool the reformed gas. ) Is a fuel characterized in that the reformed gas flowing into the catalyst layer (31) is cooled to a temperature at which the outlet temperature of the catalyst layer (31) becomes lower than the side reaction generation temperature. Battery system. 11. The reformed gas cooling means (33) of the carbon monoxide remover (30) controls the reformed gas flowing into the catalyst layer (31) at a temperature not higher than the reaction start temperature in the catalyst layer (31). The fuel cell system according to claim 10, wherein the fuel cell system is configured to be cooled. 12. A catalyst layer (31) of a carbon monoxide remover (30) is divided at an intermediate portion of a reformed gas passage, and the divided portion is divided into
The fuel cell system according to claim 10 or 11, characterized in that a second reformed gas cooling means (36) is provided. 13. The reformed gas cooling means (33, 36) of the carbon monoxide remover (30) is a heat exchanger for recovering the heat of the reformed gas flowing into the catalyst layer (31) into a heat recovery medium. The fuel cell system according to claim 10, 11 or 12, which is configured. 14. A reforming gas cooling means (33, 36) of a carbon monoxide remover (30), comprising a fuel cell cooling water circuit for circulating fuel cell cooling water for cooling the fuel cell (10),
14. The fuel cell system according to claim 13, which is a heat exchanger using the fuel cell cooling water as a heat recovery medium from the reformed gas. 15. A reforming gas cooling means (33, 36) of a carbon monoxide remover (30) is provided with a hot water circuit in which a heat transfer water to which exhaust heat of a fuel cell (10) is given is circulated,
The fuel cell system according to claim 13, which is a heat exchanger using the heat transfer water as a heat recovery medium from the reformed gas. 16. The reformed gas cooling means (33, 36) of the carbon monoxide remover (30) heats the air or oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) from the reformed gas. The fuel cell system according to claim 13, wherein the fuel cell system is a heat exchanger as a recovery medium. 17. The reformed gas cooling means (33, 36) of the carbon monoxide remover (30) is a heat exchanger using the exhaust gas of the fuel cell (10) as a heat recovery medium from the reformed gas. The fuel cell system according to claim 13, wherein: 18. The carbon monoxide remover (30) has a casing (35) in which the reformed gas cooling means (33, 36) and the catalyst layer (31) are integrated.
It is provided in the inside, The claim 10 to 1 characterized by the above-mentioned.
7. The fuel cell system according to any one of 7. 19. The reformed gas cooling means (33, 36) of the carbon monoxide remover (30) starts cooling the reformed gas flowing into the catalyst layer (31) after a lapse of a predetermined time from system startup. The fuel cell system according to claim 10, wherein the fuel cell system is configured as described above.