JP3960001B2 - Carbon monoxide remover and fuel cell system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a carbon monoxide remover that substantially removes carbon monoxide by sufficiently reducing the concentration of carbon monoxide in the reformed gas supplied to the fuel cell in the fuel cell system, and to remove the carbon monoxide. The present invention relates to a fuel cell system provided with a vessel.
[0002]
[Prior art]
  In general, a fuel cell system supplies a fuel cell with a hydrogen-rich reformed gas generated by reforming a source gas such as city gas, and water is generated by a reaction between hydrogen in the reformed gas and oxygen in the air. It is configured to convert energy when it is possible to electricity. In this system, a reformer is generally used to generate a hydrogen-rich reformed gas from a source gas from which sulfur compounds have been removed in a reforming process before supplying the source gas to the fuel cell.
[0003]
  Here, in a polymer electrolyte fuel cell having a hydrogen electrode and an oxygen electrode arranged across an electrolyte made of a solid polymer, if carbon monoxide is mixed in the reformed gas used as fuel, Carbon monoxide poisons the hydrogen electrode catalyst of the fuel cell, reducing the power generation efficiency of the cell. 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 solid polymer fuel cell, carbon monoxide is formed downstream of the reformer. Transformers are used that transform carbon into carbon dioxide.
[0004]
  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. It is difficult to achieve the level. For this reason, generally, after mixing air with the reformed gas generated by the reformer and the shifter, it is passed through a carbon monoxide remover including a selective oxidation catalyst that selectively oxidizes carbon monoxide. Thus, the remaining carbon monoxide is substantially removed. Specifically, in the carbon monoxide remover, carbon monoxide in the reformed gas is removed in the presence of a selective oxidation catalyst.
      CO + (1/2) O₂→ CO₂+ 282.9KJ / mol ...(1)
It is made to remove by the combustion reaction shown by this reaction formula.
[0005]
[Problems to be solved by the invention]
  The reaction in the carbon monoxide remover(1)As shown in the equation, the reaction is accompanied by a large exotherm, but if the reaction temperature rises excessively (for example, 200 ° C. or higher) depending on the outcome of the reaction,
      H₂+ (1/2) O₂→ H₂O + 241.8KJ / mol…(2)
      CO + 3H₂→ CH₄+ H₂O + 205.8 KJ / mol ...(3)
      CO₂+ 4H₂→ CH₄+ 2H₂O + 164.6KJ / mol…(Four)
As a result of the side reactions shown in the above formulas, the consumption of hydrogen gas as fuel for the fuel cell may reduce the efficiency or generate methane. Conversely, if the reaction temperature is too low,(1)The reaction of the formula becomes difficult to proceed. From the above, it is considered that the reaction temperature in the carbon monoxide remover is ideally kept in a temperature range around 150 ° C.
[0006]
  Based on such a concept, various techniques have been proposed in the past in order to realize a reaction in the above temperature range in a carbon monoxide remover. For example, Japanese Patent Laid-Open No. 2000-203801 discloses a heat exchangeable catalyst device (carbon monoxide remover) in which a catalyst layer is formed on a plate or a metal honeycomb, and the catalyst is supported on the heat exchange fins. The structure to be described is described. In this apparatus, the heat of reaction when carbon monoxide is converted to carbon dioxide is recovered by a heat recovery medium through heat exchange fins, thereby lowering the temperature of the reaction section.
[0007]
  However, when the catalyst is cooled during the reaction, a temperature distribution is likely to occur in the catalyst, and it is difficult to maintain a uniform reaction temperature. That is, a hot spot or a cold spot due to temperature unevenness occurs in the catalyst, and a uniform oxidation reaction hardly occurs. For example, when water is allowed to flow around the fin as a heat recovery medium, 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 place away from the water is It becomes high temperature and side reaction occurs.
[0008]
  As described above, in the conventional carbon monoxide remover, it is theoretically preferable to maintain the reaction temperature in a predetermined temperature range, but in reality, the temperature range is maintained and uniform. It was extremely difficult to make the reaction take place. The present invention was devised in view of such problems, and the object of the present invention is to suppress side reactions due to excessive temperature rise and reliably prevent performance degradation in a carbon monoxide remover. It is to be.
[0009]
[Means for Solving the Problems]
  The present invention eliminates carbon monoxide by supplying the carbon monoxide remover (30) with the reformed gas cooled to a predetermined temperature or lower in advance without cooling the catalyst layer (31) itself during the reaction. The temperature of the reactor (30) is prevented from excessively rising.
[0010]
  Specifically, from the first taken by the present invention8thThis solution is based on a carbon monoxide remover (30) that oxidizes and removes carbon monoxide in the reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst.
[0011]
  The carbon monoxide remover (30) according to the first solving means includes a heat insulating layer (32) covering the periphery of the catalyst layer (31) containing the catalyst, and a catalyst layer (31 in the reformed gas flow path). ) And a reformed gas cooling means (33) for cooling the reformed gas, which is upstream of the reformed gas.Catalyst layer (31) In the state where the temperature of is higher than the reaction start temperature,The reformed gas flowing into the catalyst layer (31) is cooled to a temperature at which the outlet temperature of the catalyst layer (31) is lower than the side reaction generation temperature.It is what.For example, when the side reaction generation temperature is about 200 ° C., the reformed gas is cooled to a temperature of about 80 ° C. to 90 ° C. or lower by the reformed gas cooling means (33) and charged into the catalyst layer (31). Good.
[0012]
  In this first solution, the reformed gas flowing into the carbon monoxide remover (30) is cooled by the reformed gas cooling means (33) and then passes through the catalyst layer (31). When the reformed gas passes through the catalyst layer (31), the temperature of the reformed gas increases 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 (31) is insulated from the surroundings so that the temperature rises from the inlet side to the outlet side by leaving it to an exothermic reaction, but the catalyst layer (31) is not cooled forcibly. Therefore, the temperature of the catalyst layer (31) becomes substantially uniform on the surface orthogonal to the flow direction of the reformed gas. For this reason, generation | occurrence | production of a hot spot and a cold spot is prevented.
[0013]
  Also,In the first solution, the reformed gas cooling means (33) But the catalyst layer (31) In the state where the temperature of the catalyst layer is higher than the reaction start temperature, (31) The reformed gas flowing into the catalyst layer (31) In addition to cooling to a temperature at which the outlet temperature of the catalyst becomes lower than the side reaction occurrence temperature, the catalyst layer (31) It is comprised so that it may cool to the temperature below the reaction start temperature in.For example, when the side reaction generation temperature is about 200 ° C. and the reaction start temperature is about 100 ° C., the reformed gas is cooled to a temperature of about 80 ° C. to 90 ° C. or lower by the reformed gas cooling means (33). Good.
[0014]
  thisFirstIn this solution, the reformed gas is cooled to a temperature not higher than the reaction start temperature in the catalyst layer (31) by the reformed gas cooling means (33) and flows into the catalyst layer (31). During operation, since the temperature of the catalyst layer (31) is increased by the reaction heat, the reformed gas absorbs this heat and rises to a temperature higher than the reaction start temperature, and the reaction is started. Thereafter, the temperature of the reformed gas rises to a temperature lower than the side reaction generation temperature, and flows out of the catalyst layer (31).
[0015]
  The present invention also tookSecondThe solution ofFirstIn this solution, the catalyst layer (31) is divided at an intermediate portion of the reformed gas flow path, and a second reformed gas cooling means (36) is provided at the divided portion. .
[0016]
  thisSecondIn this solution, the reformed gas is cooled to a predetermined temperature on the upstream side of the catalyst layer (31), then flows into the catalyst layer (31) and rises in temperature, and then the intermediate portion of the catalyst layer (31). It is cooled again by the second reformed gas cooling means (36). Further, after passing through the catalyst layer (31), it flows out of the catalyst layer (31) at a temperature lower than the side reaction occurrence temperature.
[0017]
  The present invention also tookThirdThe solution of1st or 2ndIn this solution, the reformed gas cooling means (33, 36) is configured as a heat exchanger that recovers the heat of the reformed gas flowing into the catalyst layer (31) to the heat recovery medium. .
[0018]
  The present invention also took4th to 7thThe solution ofThirdWhich specifies the heat recovery medium of the solution of4thThe solution ofThirdIn this solution, the reformed gas cooling means (33, 36) is a heat exchanger using fuel cell cooling water as a heat recovery medium from the reformed gas.
[0019]
  The present invention also took5thThe solution ofThirdIn the solution, the reformed gas cooling means (33, 36) is a heat exchanger that uses heat transfer water to which exhaust heat from the fuel cell (10) is applied as a heat recovery medium from the reformed gas. It is said. This heat transfer water can be used for hot water supply, for example.
[0020]
  The present invention also took6thThe solution ofThirdIn this solution, the reformed gas cooling means (33, 36) is a heat exchanger that uses air or an oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) as a heat recovery medium from the reformed gas. It is characterized by that.
[0021]
  The present invention also took7thThe solution ofThirdIn this solution, 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 hydrogen electrode exhaust gas or oxygen electrode exhaust gas, or a mixture thereof.
[0022]
  the above3rd to 7thIn this solution, the reformed gas is heat from fuel cell cooling water, heat transfer water, air or oxygen-containing gas, or battery exhaust gas flowing through a heat exchanger provided as a reformed gas cooling means (33, 36). It is cooled to a predetermined temperature by the recovery medium, flows into the catalyst layer (31), and flows out from the catalyst layer (31) at a temperature lower than the side reaction occurrence temperature.
[0023]
  The present invention also took8thThe solution of the above is from the first7thIn any one of the solution means, the reformed gas cooling means (33, 36) and the catalyst layer (31) are provided in an integral casing (35).
[0024]
  this8thIn the solution, the reformed gas flowing into the carbon monoxide remover (30) is cooled by the reformed gas cooling means (33, 36) in the integral casing (35), and the catalyst layer ( As it passes through 31), carbon monoxide reacts with oxygen and is removed.
[0025]
  Next, the present invention took9th to 17thThe solution is a fuel cell comprising a carbon monoxide remover (30) for oxidizing and removing carbon monoxide in the reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst. The system is assumed.
[0026]
  And9thThe fuel cell system according to the solution corresponds to the first solution, and specifically, the carbon monoxide remover (30) covers the periphery of the catalyst layer (31) containing the catalyst. A heat insulating layer (32), and a reformed gas cooling means (33) for cooling the reformed gas located upstream of the catalyst layer (31) in the reformed gas flow path. 33)Catalyst layer (31) In the state where the temperature of is higher than the reaction start temperature,The reformed gas flowing into the catalyst layer (31) is cooled to a temperature at which the outlet temperature of the catalyst layer (31) is lower than the side reaction generation temperature.It is what.
[0027]
  Also,In the ninth solution, a carbon monoxide remover (30) Reforming gas cooling means (33) But the catalyst layer (31) In the state where the temperature of the catalyst layer is higher than the reaction start temperature, (31) The reformed gas flowing into the catalyst layer (31) In addition to cooling to a temperature at which the outlet temperature of the catalyst becomes lower than the side reaction occurrence temperature, the catalyst layer (31) It is comprised so that it may cool to the temperature below the reaction start temperature in.
[0028]
  The present invention also took10thThe solution ofSecondSpecifically, it corresponds to the above solution.9thIn this solution, the catalyst layer (31) of the carbon monoxide remover (30) is divided at the middle portion of the reformed gas flow path, and the second reformed gas cooling means (36) is provided at the divided portion. It is characterized by being provided.
[0029]
  The present invention also took11thThe solution ofThirdSpecifically, it corresponds to the above solution.9th or 10thIn this solution, the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) serves as a heat exchanger that recovers the heat of the reformed gas flowing into the catalyst layer (31) to a heat recovery medium. It is characterized by being composed.
[0030]
  The present invention also took12thThe solution of4thSpecifically, it corresponds to the above solution.11thThe fuel cell cooling water circuit in which the fuel cell cooling water for cooling the fuel cell (10) circulates, and the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) includes It is a heat exchanger using battery cooling water as a heat recovery medium from the reformed gas.
[0031]
  The present invention also took13thThe solution of5thSpecifically, it corresponds to the above solution.11thIn the solution, a hot water circuit in which heat transfer water to which exhaust heat from the fuel cell (10) is given circulates is circulated, and the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) includes the above heat It is a heat exchanger that uses a water medium as a heat recovery medium from the reformed gas.
[0032]
  The present invention also took14thThe solution of6thSpecifically, it corresponds to the above solution.11thIn this solution, the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) converts the air or oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) into heat from the reformed gas. It is a heat exchanger used as a recovery medium.
[0033]
  The present invention also took15thThe solution of7thSpecifically, it corresponds to the above solution.11thIn the above solution, the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) is a heat exchanger that uses the exhaust gas of the fuel cell (10) as a heat recovery medium from the reformed gas. It is characterized by. In this case, it is possible to use either hydrogen electrode exhaust gas or oxygen electrode exhaust gas, or a mixture thereof.
[0034]
  The present invention also took16thThe solution of8thSpecifically, it corresponds to the above solution.9th to 15thIn any one of the solutions, the carbon monoxide remover (30) is provided with the reformed gas cooling means (33, 36) and the catalyst layer (31) in an integral casing (35). It is characterized by.
[0035]
  Furthermore, the present invention has taken17thThe solution of9th to 16thIn any one of the solution means, the reformed gas cooling means (33, 36) of the carbon monoxide remover (30) removes the reformed gas flowing into the catalyst layer (31).After starting the system, the catalyst layer ( 31 ) After the temperature becomes higher than the reaction start temperatureIt is characterized by being configured to start cooling.
[0036]
  In this seventeenth solution, since the high-temperature reformed gas from the transformer (22) is not cooled at the time of starting the system, the catalyst layer (31) rises to the reaction start temperature or higher after a predetermined time has elapsed since the start. The reaction is started. Once the reaction starts, the reformed gas is cooled by the reformed gas cooling means (33) and then heated to a temperature higher than the reaction start temperature by the reaction heat in the catalyst layer (31), and the reaction continues. At this time, the outlet temperature does not rise above the side reaction generation temperature.
[0037]
【The invention's effect】
  1st and above9thAccording to the solution, the periphery of the catalyst layer (31) is covered with the heat insulating layer (32), and the reformed gas flowing into the catalyst layer (31) is cooled by the reformed gas cooling means (33). Yes. For this reason, 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, the occurrence of a hot spot or a cold spot can be prevented, thereby preventing the occurrence of a problem that a side reaction occurs in the hot spot or the CO concentration is not sufficiently reduced in the cold spot. In other words, in the conventional configuration in which the temperature of the catalyst layer (31) is made uniform throughout, it is extremely difficult to suppress side reactions and prevent performance degradation, whereas the catalyst layer (31) By adopting a configuration that allows a temperature gradient from the inlet side to the outlet side in a thermally insulated state, it is possible to suppress side reactions and prevent performance degradation.
[0038]
  In addition, as described above, since carbon monoxide can be substantially removed by sufficiently reducing the carbon monoxide concentration in the carbon monoxide remover (30), occurrence of catalyst poisoning in the fuel cell (10) Can be reliably prevented.
[0039]
  Also, the reformed gasBy cooling to a temperature lower than the reaction start temperature in the catalyst layer (31), it is possible to effectively prevent the reformed gas from rising to a temperature higher than the side reaction occurrence temperature, and to reform during operation. Since the gas rises to a temperature higher than the reaction start temperature by reaction heat, it is possible to prevent the carbon monoxide removal performance from being lowered.
[0040]
  Also, above2nd and 10thAccording to this solution, since the second reformed gas cooling means (36) is provided in the middle part of the catalyst layer (31), the reformed gas is further prevented from rising to a temperature higher than the side reaction generation temperature. It can be effectively prevented. For this reason, in the case of a system in which a reformed gas having a relatively high carbon monoxide concentration is fed into the carbon monoxide remover (30), the outlet temperature tends to rise higher than the side reaction occurrence temperature, Temperature rise can be prevented more reliably.
[0041]
  Also, above3rd to 7thSolution of11th to 15thAccording to the solution, by using fuel cell cooling water, heat transfer water, air or oxygen-containing gas, or battery exhaust gas as a heat recovery medium, it is possible to prevent a decrease in performance while suppressing the occurrence of side reactions, It is possible to prevent the configuration from becoming complicated.
[0042]
  Also, above8th and 16thSince 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) is Can be simple.
[0043]
  Also, above17thAccording to the solution, since the reformed gas is not cooled at the start-up and the cooling is started after a predetermined time has elapsed from the start-up, it is not necessary to provide a means for heating the reformed gas at the start-up. It is possible to prevent the configuration from becoming complicated. In addition, as in each of the above solutions, the system can be continuously operated in an appropriate state without causing side reactions due to excessive temperature rises or conversely lowering the temperature and reducing the performance. it can.
[0044]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
  Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.
[0045]
  FIG. 1 is a circuit block diagram of the fuel cell system (1) according to the first embodiment. As shown in the figure, the fuel cell system (1) includes a fuel cell (10), a reformer (20), a cooling water circuit (40), and a hot water storage circuit (50).
[0046]
  The fuel cell (10) is configured as a solid polymer electrolyte type. In this fuel cell (10), a unit cell is formed by forming electrodes by dispersing catalyst particles on both surfaces of an electrolyte membrane made of, for example, a fluorine-based polymer film. One of the electrodes on the surface of the electrolyte membrane is a hydrogen electrode (anode), and the other is an oxygen electrode (cathode). The fuel cell (10) constitutes a stack (collective cell) in which unit cells are stacked via a bipolar plate. The structure of the fuel cell (10) described above is not shown in FIG.
[0047]
  In the 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. Has been. An air passage (2) is connected to the oxygen electrode side gas passage (11) via an air supply pipe (13) on the inlet side, and an oxygen electrode exhaust pipe (14) is connected to the outlet side thereof. On the other hand, the reformed gas passage (3) is connected to the hydrogen electrode side gas passage (12) via the hydrogen supply pipe (15) on the inlet side, and the hydrogen electrode exhaust pipe (16) is connected to the outlet side thereof. It is connected.
[0048]
  The oxygen electrode exhaust pipe (14) and the hydrogen electrode exhaust pipe (16) are connected to the fuel cell exhaust pipe (17). The fuel cell exhaust pipe (17) is connected to the combustor (18) and the battery exhaust gas cooling heat exchanger (19), and is configured to cool and discharge the fuel cell exhaust gas after combustion. The combustor (18) is used for oxygen remaining in the oxygen electrode exhaust gas (O₂), Hydrogen remaining in the hydrogen electrode exhaust gas (H₂). The exhaust gas cooling heat exchanger (19) collects the amount of heat of the combustion gas and stores hot water.
[0049]
  The reformer (20) is provided on the reformed gas passage (3), and from the upstream side, the reformer (21) and the transformer (22) integrally shown in the figure, and the carbon monoxide remover. (30). The reformer (21) is connected to a supply source of city gas that is a raw material gas. A desulfurizer (not shown) for removing sulfur compound components in the city gas is connected between the reformer (21) and the city gas supply source as necessary.
[0050]
  The reformer (21), for example, reforms mainly containing carbon dioxide and hydrogen by performing a reforming reaction while heating a desulfurized city gas and water (steam) supplied from a tank (not shown) with a burner. Generates quality gas. The reformed gas produced by the reformer (21) also contains carbon monoxide, and the transformer (22) converts the carbon monoxide into carbon dioxide.
[0051]
  The carbon monoxide remover (30) reduces the power generation efficiency of the fuel cell system (1) if carbon monoxide remains in the reformed gas. It is configured to be oxidized and removed in the presence of. The carbon monoxide remover (30) includes a catalyst layer (31) containing the above catalyst (in the figure, the block of the catalyst layer indicates “carbon monoxide remover”), and at least the catalyst layer ( A heat insulating layer (32) covering the periphery of 31) (see FIG. 2), 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 used for the reformed gas flowing into the catalyst layer (31) of the carbon monoxide remover (30), and the outlet temperature of the catalyst layer (31) is higher than the side reaction generation temperature. It is configured to cool to a lower temperature.
[0052]
  On the downstream side of the catalyst layer (31) of the carbon monoxide remover (30), an auxiliary heat exchanger for cooling the reformed gas that has flowed out of the catalyst layer (31) to the input temperature to the fuel cell (10). (34) is provided. 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 exchanger (34). The exchanger (34) is conventionally used.
[0053]
  The air passage (2) branches at two locations upstream of the fuel cell (10), and connects the upstream side of the reformer (21) and the catalyst layer (31) of the carbon monoxide remover (30). The upstream side is connected to the reformed gas passage (3).
[0054]
  The cooling water circuit (40) is a closed circuit filled with battery cooling water. By circulating the battery cooling water in the cooling water circuit (40), the fuel cell (10) is brought to a predetermined operating temperature. Kept. The cooling water circuit (40) includes a battery cooling water tank (41), a fuel cell (10), a reformed gas cooling heat exchanger (33) and an auxiliary heat exchanger (34), a battery exhaust gas cooling heat exchanger (19 ) And a hot water heat exchanger (51) in this order. In addition, a cooling water pump (not shown) is provided in this circuit.
[0055]
  The hot water heat exchanger (51) is connected to a hot water storage tank (52), and 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) is a hot water heat exchanger for the heat of battery cooling water heated in the reformed gas cooling heat exchanger (33), auxiliary heat exchanger (34) and battery exhaust gas cooling heat exchanger (19). The hot water storage water (heat medium water) is supplied to the hot water storage circuit (50) in the vessel (51), 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.
[0056]
  Next, the carbon monoxide remover (30) will be specifically described. FIG. 2 is a perspective view conceptually showing the configuration of the carbon monoxide remover (30), and FIGS. 3 and 4 are diagrams showing an example of the specific configuration. 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. It is the IV-IV sectional view taken on the line of (b).
[0057]
  In the figure, a carbon monoxide remover (30) includes a catalyst layer (31) containing the carbon monoxide selective oxidation catalyst, and a reformed gas cooling heat exchanger (33) located upstream of the catalyst layer (31). ) And an auxiliary heat exchanger (34) located downstream of the catalyst layer (31) in one casing (35). Further, in the casing (35), a heat insulating layer (32) that covers the catalyst layer (31) and the heat exchangers (33, 34) as a whole is provided. The heat insulating layer (32) is omitted in FIG. 3 for convenience. The heat insulating layer (32) may be at least as long as it covers the periphery of the catalyst layer (31), and is not necessarily provided around the heat exchangers (33, 34).
[0058]
  Each of the heat exchangers (33, 34) is a plate fin coil type heat exchanger as shown in FIG. 4, and each heat exchanger (33, 34) has fins (33a, 34a) arranged in two upper and lower stages. Has been placed. The pipes (42) of the cooling water circuit (40) are connected to these heat exchangers (33, 34). Specifically, the lower stage side of the auxiliary heat exchanger (34) and the lower stage 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). 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.
[0059]
  As described above, the reformed gas cooling heat exchanger (33) located on the upstream side of the catalyst layer (31) converts the heat of the reformed gas flowing into the catalyst layer (31) into a heat recovery medium (this embodiment). In the case of 1, the reformed gas cooling means is configured to recover the reformed gas to a predetermined temperature by collecting it in battery cooling water). Specifically, the heat exchanger (33) is provided with an outlet of the catalyst layer (31) that reaches the highest temperature by cooling the reformed gas that flows into the catalyst layer (31), which is insulated from the surroundings, to, for example, 90 ° C. Also on the side, the temperature is set to be lower than the side reaction generation temperature (for example, 200 ° C.). Moreover, in this Embodiment 1, the reaction start temperature in a catalyst layer (31) is 100 degreeC, for example. That is, the reformed gas cooling heat exchanger (33) cools the reformed gas flowing into the catalyst layer (31) to a temperature not higher than the reaction start temperature in the catalyst layer (31).
[0060]
      -Driving action-
    Next, the operation of the fuel cell system (1) during power generation will be described.
[0061]
  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 and the gas is mixed with air and sent to the reformer (21). It is done. In the reformer (21), a raw material gas and water vapor supplied from a tank (not shown) are subjected to a steam reforming reaction while being heated by a burner to produce a reformed gas mainly containing carbon dioxide and hydrogen.
[0062]
  This reformed gas also contains carbon monoxide as described above, but the carbon monoxide component in the gas is reduced in the transformer (22). In the first embodiment, the composition of the reformed gas exiting the transformer (22) is, for example,
  CH₄ : 0.7%
  H₂O: 26.03%
  H₂   : 35.8%
  CO: 0.52%
  CO₂ : 12.39%
  N₂   : 24.57%
Thus, the concentration of carbon monoxide is reduced to 0.52%. The reformed gas further flows to the carbon monoxide remover (30), and carbon monoxide is removed by oxidation. At this time, air is mixed with the reformed gas, and O at that time₂/ CO (volume ratio of oxygen to carbon monoxide) is generally set to about 1.0 to 1.5, whereas it is generally about 2.0 to 2.5. That is, in the present embodiment, the amount of oxygen input in the carbon monoxide remover (30) is made smaller than before.
[0063]
  The reformed gas exiting the carbon monoxide remover (30) is supplied to the fuel cell (10) with a carbon monoxide concentration lower than the target value of 10 ppm. 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 or the like (not shown) through the air supply pipe (13). When combined, the ions generated at that time are converted into the charges of the cathode and the anode to generate electric power.
[0064]
  In the reformed gas cooling heat exchanger (33), the reformed gas flowing into the carbon monoxide remover (30) exchanges heat with the battery cooling water (about 75 ° C.) after cooling the fuel cell (10). And cooled to a temperature of about 80 ° C. to 90 ° C. This temperature is lower than the reaction start temperature (about 100 ° C.) in the catalyst layer (31). By setting such a temperature, the outlet temperature of the catalyst layer (31) is lower than the side reaction occurrence temperature. I try to lower it.
[0065]
  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 in a high temperature state that flows out of the transformer (22). Supplied to the carbon monoxide remover (30). For this reason, the temperature of the catalyst layer (31) becomes higher than the reaction start temperature after a predetermined time has elapsed from the start, and the reaction continues.
[0066]
  Thus, during operation of the fuel cell system (1), the temperature of the catalyst layer (31) is higher than the reaction start temperature due to reaction heat, and is cooled by the reformed gas cooling heat exchanger (33). When the reformed gas flows into the catalyst layer (31) of the carbon monoxide remover (30), the temperature rises due to the reaction heat and the reaction is started. The reformed gas gradually increases in temperature from the inlet side to the outlet side of the catalyst layer (31), while at the lower temperature than the temperature (200 ° C.) at which the side reaction occurs (from the catalyst layer (31)). leak.
[0067]
  As described above, during the operation of the system, the reformed gas flowing into the catalyst layer (31) is cooled in advance without cooling the catalyst layer (31) in a state where the catalyst layer (31) is insulated. As a result, a substantially uniform temperature gradient is generated in the catalyst layer (31) from the inlet side toward the outlet side. On the other hand, the catalyst layer (31) has a substantially uniform temperature in the plane direction orthogonal to the flow of the reformed gas, and no cold spot or hot spot is generated. Therefore, as a whole, a stable oxidation reaction occurs, and an excessive increase in temperature is suppressed. Therefore, no side reaction occurs in the carbon monoxide remover (30), and performance is not deteriorated.
[0068]
  In addition, the reformed gas flowing out from the catalyst layer (31) is cooled to the charging temperature (about 80 ° C.) to the fuel cell (10) in the auxiliary cooling heat exchanger (34), and the hydrogen in the fuel cell (10) is cooled. It flows into the pole side gas passage (12). The hydrogen electrode exhaust gas and oxygen electrode exhaust gas of the fuel cell merge in the fuel cell exhaust pipe (17), burn in the combustor (18), and then exchange heat with the battery cooling water in the battery exhaust gas cooling heat exchanger (19). Then it is cooled and exhausted.
[0069]
  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 the hot water heat exchanger (51) After cooling, the battery cooling water tank (41) is returned. The cooling water returned to the battery cooling water tank (41) cools the fuel cell (10) and then flows to the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34) to reform again. Cool the gas.
[0070]
  In the hot water heat exchanger (51), the battery cooling water and the hot water supply water exchange heat, and the hot water supply water is heated. This hot water supply water is stored in a hot water storage tank (52) and used for hot water supply as necessary.
[0071]
      -Effect of Embodiment 1-
  According to the first embodiment, the catalyst layer (31) is covered with the heat insulating layer (32), and the reformed gas flowing into the catalyst layer (31) is cooled by the reformed gas cooling heat exchanger (33). As a result, the temperature rises from the inlet side to the outlet side of the catalyst layer (31), but the temperature is almost uniform in the plane direction orthogonal to the flow direction of the reformed gas. And cold spots can be prevented. Therefore, it is possible to prevent the occurrence of a problem that a side reaction occurs in the hot spot or the CO concentration is not sufficiently reduced in the cold spot.
[0072]
  That is, in the configuration in which the catalyst layer (31) is made to have a uniform temperature as a whole, it is difficult to suppress side reactions and prevent performance degradation, while the catalyst layer (31) is insulated. By adopting a configuration that allows a substantially uniform temperature gradient from the inlet side to the outlet side, side reactions can be suppressed and performance degradation can be prevented.
[0073]
  Conventionally, O₂/ CO (volume ratio of oxygen and carbon monoxide) had to be set to about 2.0 to 2.5, but according to the present embodiment, the reaction is stable, so that O₂/ CO is set to about 1.0 to 1.5, and O₂ Even if the input amount is reduced, the target value (10 ppm) can be achieved. As a result, the hydrogen yield is increased and the efficiency is improved.
[0074]
  In addition, since the reformed gas is cooled to a temperature (about 80 ° C. to 90 ° C.) lower than the reaction start temperature (about 100 ° C.) in the catalyst layer (31), the reformed gas has a side reaction occurrence temperature. It is possible to effectively prevent the temperature from rising to (200 ° C.) or higher. In addition, even with such a temperature setting, the reformed gas rises to a temperature higher than the reaction start temperature by reaction heat during operation, so that it is possible to prevent the carbon monoxide removal performance from being lowered.
[0075]
  Further, according to the present embodiment, in the carbon monoxide remover (30), the carbon monoxide can be substantially removed by sufficiently reducing the carbon monoxide concentration while suppressing side reactions, so that the fuel cell (10) The occurrence of catalyst poisoning can be reliably prevented.
[0076]
  Furthermore, in the first embodiment, a complicated configuration for cooling the catalyst by inserting fins into the catalyst layer and a complicated structure for circulating water to cool the catalyst layer are unnecessary, so the configuration is simplified. it can.
[0077]
      -Modification of Embodiment 1-
  (Modification 1)
  FIG. 5 is a perspective view conceptually showing the structure of a modified example of the carbon monoxide remover (30). In this carbon monoxide remover (30), the catalyst layer (31) is divided at the middle part of the reformed gas flow path, and the middle part between the preceding catalyst layer (31a) and the latter catalyst layer (31b) A second reformed gas cooling heat exchanger (36) is provided as a reformed gas cooling means. That is, the carbon monoxide remover (30) includes the reformed gas cooling heat exchanger (33) on the upstream side of the catalyst layer (31) described in the first embodiment and the auxiliary on the downstream side of the catalyst layer (31). In addition to the heat exchanger (34), a second reformed gas cooling heat exchanger (36) is provided in the middle of the catalyst layer (31).
[0078]
  In each of the heat exchangers (33, 34, 36), the battery cooling water flows as in the first embodiment. The battery cooling water and the reformed gas exchange heat to cool the reformed gas.
[0079]
  Further, the carbon monoxide remover (30) is configured such that air is blown into the downstream catalyst layer (31b) at the portion where the catalyst layer (31) is divided. In other words, oxygen flowing into the carbon monoxide remover (30) together with the reformed gas is consumed in the reaction in the previous catalyst layer (31a), so oxygen is supplied to the reaction in the subsequent catalyst layer (31b). Like to do.
[0080]
  In this modification, the reformed gas is cooled to a predetermined temperature on the upstream side of the catalyst layer (31), and then flows into the previous catalyst layer (31a) to rise in temperature, and then both catalyst layers (31a, 31b) ) Is cooled again by the second reformed gas cooling means (36) at the intermediate portion of the gas, and then flows out of the catalyst layer at a temperature lower than the side reaction generation temperature after passing through the latter catalyst layer (31b). The temperature can be set as follows. For this reason, the carbon monoxide remover (30) is provided with a reformed gas when the reformed gas supplied from the transformer (22) contains, for example, more than 0.6% carbon monoxide. It is possible to effectively prevent the temperature from rising to a temperature higher than the side reaction occurrence temperature. In other words, in the case of a system in which a reformed gas having a relatively high CO gas concentration containing more than 0.6% of carbon monoxide is processed by the carbon monoxide remover (30), the amount of oxygen input also increases. While the outlet temperature tends to rise higher than the side reaction generation temperature, it is possible to reliably prevent an excessive temperature rise.
[0081]
  On the other hand, the first embodiment is suitable for processing a reformed gas containing about 0.4% to 0.6% carbon monoxide, and the configuration is complicated compared to this modification. Can be prevented.
[0082]
  (Modification 2)
  The reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34) are configured to be connected in parallel to each other in the cooling water circuit (40) in FIGS. 1 and 3, but these heat exchangers ( 33, 34) may be connected in series.
[0083]
  FIG. 6 shows an example in which both heat exchangers (33, 34) are connected in series. Specifically, the upper stage side of the auxiliary heat exchanger (34) and the lower stage side of the reformed gas cooling heat exchanger (33) are connected by an intermediate pipe, while the lower stage side of the auxiliary heat exchanger (34) and the reformer are connected. The upper side of the gas cooling heat exchanger (33) is connected to the cooling water pipe (42), and is configured on the inlet side and outlet side of the cooling water in the carbon monoxide remover (30).
[0084]
  Even if it does in this way, the effect equivalent to the carbon monoxide remover (30) of FIG. 3 can be acquired.
[0085]
Second Embodiment of the Invention
  In Embodiment 2 of the present invention, the hot water storage water (heat transfer water) of the hot water storage circuit (50) to which the exhaust heat of the fuel cell is applied is used as the heat recovery medium from the reformed gas in the reformed gas cooling heat exchanger (33) It is made to use as.
[0086]
  The second embodiment differs from the fuel cell system (1) of the first embodiment in the configuration of the cooling water circuit (40) and the hot water storage circuit (50). In the second embodiment, the cooling water circuit (40) is a closed circuit in which a battery cooling water tank (41), a fuel cell (10), and a hot water heat exchanger (51) are sequentially connected as shown in FIG. It is configured. The cooling water circuit (40) is provided with a cooling water pump (not shown).
[0087]
  The hot water storage circuit (50) includes a 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 battery exhaust gas cooling heat exchange. The device (19) is configured in a closed circuit connected in order. A hot water pump (not shown) is provided in the hot water storage circuit (50).
[0088]
  In this fuel cell system (1), a reformer (21), a transformer (22), a carbon monoxide remover (30), a fuel cell (10), etc., a cooling water circuit (40) and a hot water storage circuit (50) The other parts are configured in the same manner as in the first embodiment.
[0089]
  In the second embodiment, the hot water stored in the hot water storage tank (52) is heated to about 70 ° C. by the hot water heat exchanger (51). The hot water storage 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) flows upstream of the catalyst layer (31). Cooling is performed on the side and the downstream side in the same manner as in the first embodiment. The hot water storage water heated when cooling the reformed gas 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). The temperature of the hot water stored in the hot water storage tank (52) is set so as to be stored at a temperature of about 85 ° C., although the temperature slightly varies depending on the supply of water.
[0090]
  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 charged into the catalyst layer (31). In this case, hot spots and cold spots can be prevented from occurring. For this reason, it is possible to prevent a decrease in carbon monoxide removal performance while suppressing the occurrence of side reactions, and to reliably prevent catalyst poisoning in the fuel cell (10).
[0091]
Embodiment 3 of the Invention
  In Embodiment 3 of the present invention, air or an oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) is used as a heat recovery medium from the reformed gas in the reformed gas cooling heat exchanger (33). It is a thing.
[0092]
  In the third embodiment, the configurations of the air passage (2), the cooling water circuit (40) and the hot water storage circuit (50) are different from the fuel cell systems (1) of the first and second embodiments. is there. In other words, as shown in FIG. 8, the air passage (2) includes the reformed gas cooling heat exchanger (33) and the auxiliary air using heat as a heat recovery medium from the reformed gas.Heat exchanger(34) and then flow into the oxygen electrode side gas passage (11) of the fuel cell (10), while the air that has passed through the reformed gas cooling heat exchanger (33) flows upstream of the reformer (21). It is configured to be mixed with the raw material gas and flow into the reformed gas passage (3). In this way, by flowing both the air that enters the reformer (21) and the air that enters the fuel cell (10) to the reformed gas cooling heat exchanger (33), the air in the heat exchanger (33) The flow rate is increased as much as possible to obtain sufficient cooling performance for the reformed gas.
[0093]
  The cooling water circuit (40) is configured as a closed circuit in which a battery cooling water tank (41), a hot water heat exchanger (51), and a fuel cell (10) are sequentially connected. A pump is provided.
[0094]
  Further, the hot water storage circuit (50) is configured as a closed circuit in which a hot water storage tank (52), a hot water heat exchanger (51), and a battery exhaust gas cooling heat exchanger (19) are connected in order. A hot water pump (not shown) is provided in the hot water storage circuit (50).
[0095]
  In this fuel cell system (1), the other parts are configured in the same manner as in the first and second embodiments.
[0096]
  In Embodiment 3, the reformed gas flowing out from the transformer (22) is cooled by exchanging heat with air from the air passage (2) 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 a side reaction occurs when passing through the catalyst layer (31), and flows out of the catalyst layer (31). The reformed gas is cooled again by the auxiliary heat exchanger (34) (about 80 ° C.) and is introduced into the fuel cell (10). On the other hand, the air flowing through the air passage (2) is partly cooled by the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34) before the oxygen gas side of the fuel cell (10). The gas is supplied to the gas passage (11), and the remainder is mixed with the raw material gas and supplied to the reformer (21).
[0097]
  The battery cooling water exchanges heat with hot water storage water in the hot water heat exchanger (51), and further flows through the fuel cell (10) to cool the fuel cell. The battery cooling water that has cooled the fuel cell (10) returns to the battery cooling water tank (41) and repeats the above circulation.
[0098]
  The hot water storage water stored in the hot water storage tank (52) is exchanged with the battery cooling water in the hot water heat exchanger (51) when circulating in the hot water storage circuit (50), and then the battery exhaust gas cooling heat exchanger ( In 19), it is heated by exchanging heat with the combustion gas. The heated hot water storage water returns to the hot water storage tank (52) and repeats the above circulation.
[0099]
  Also in the case of Embodiment 3, the catalyst layer (31) of the carbon monoxide remover (30) is not cooled, but the reformed gas is cooled and charged into the catalyst layer (31). In this case, hot spots and cold spots can be prevented from occurring. For this reason, it is possible to prevent a decrease in carbon monoxide removal performance while suppressing the occurrence of side reactions, and to reliably prevent catalyst poisoning in the fuel cell (10).
[0100]
Embodiment 4 of the Invention
  In Embodiment 4 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).
[0101]
  The fourth embodiment is different from the fuel cell system (1) of the third embodiment in the configuration of the air passage (2) and the fuel cell exhaust pipe (17). 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) while a part of the air, as in the first and second embodiments. Is supplied to the catalyst layer (31) of the reformer (21) and the carbon monoxide remover (30). The fuel cell exhaust pipe (17) branches into two and is connected to the reformed gas cooling heat exchanger (33) and the auxiliary heat exchanger (34), and then merges to combustor (18) and The battery exhaust gas cooling heat exchanger (19) is connected.
[0102]
  Other parts such as the cooling water circuit (40) and the hot water storage circuit (50) are configured in the same manner as in the third embodiment.
[0103]
  In the fourth embodiment, the reformed gas flowing out from 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. to 90 ° C.), It 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 a side reaction occurs when passing through the catalyst layer (31), and flows out of the catalyst layer (31). The reformed gas is cooled again by the auxiliary heat exchanger (34) (about 80 ° C.) and is introduced into the fuel cell (10). On the other hand, a part of the air flowing through the air passage (2) is supplied to the reformer (21), a part is supplied to the catalyst layer (31) of the carbon monoxide remover (30), and the rest is the fuel cell. It is supplied to the oxygen electrode side gas passage (11) of (10).
[0104]
  When the fuel cell exhaust gas flows through the fuel cell exhaust pipe (17), the fuel cell exhaust gas is cooled, for example, by a fan (not shown) to a temperature of about 80 ° C. The reformed gas flowing through the carbon monoxide remover (30) is cooled before and after the catalyst layer (31) by the fuel cell exhaust gas thus cooled. The fuel cell exhaust gas may be cooled to a predetermined temperature by heat exchange with battery cooling water or hot water storage water, instead of simply cooling by air cooling.
[0105]
  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 charged into the catalyst layer (31). In this case, hot spots and cold spots can be prevented from occurring. For this reason, it is possible to prevent a decrease in carbon monoxide removal performance while suppressing the occurrence of side reactions, and to reliably prevent catalyst poisoning in the fuel cell (10).
[0106]
Other Embodiments of the Invention
  The present invention may be configured as follows with respect to the above embodiment.
[0107]
  For example, in each of the above embodiments, in the reformed gas cooling heat exchanger (33), which is a reformed gas cooling means, fuel cell cooling water, hot water, air or oxygen-containing gas, or battery exhaust gas is modified as a heat recovery medium. The quality gas is cooled to a predetermined temperature, but other heat recovery media may be used.
[0108]
  Further, the reformed gas cooling means (33) is not limited to a 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 may be used. .
[0109]
  Further, in the second to fourth embodiments, the catalyst layer (31) is divided into two as in the modification of the first embodiment, and a second reformed gas cooling heat exchanger as a reformed gas cooling means is provided therebetween. It may be provided.
[0110]
  Further, in the above embodiment, the catalyst layer (31) and the reformed gas cooling heat exchanger (33) of the carbon monoxide remover (30) are integrally formed, but they are not necessarily integrated. In the above embodiment, the auxiliary heat exchanger (34) is also integrated with the catalyst layer (31). However, the auxiliary heat exchanger (34) is not necessarily integrated with the catalyst layer (31).
[0111]
  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, the partial oxidation reforming method), and is not particularly limited. .
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of a fuel cell system according to Embodiment 1 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, wherein (a) is a left side view of the carbon monoxide remover (31), (b) is a front view, and (c). ) Is a right side view, and (d) is a plan view.
4 is a cross-sectional view taken along line IV-IV in FIG. 3 (b).
5 is a perspective view showing a modified example of the carbon monoxide remover of FIG. 2. FIG.
6 is an external view showing a modification of the carbon monoxide remover of FIG. 3, wherein (a) is a left side view of the carbon monoxide remover (31), (b) is a front view, and (c) is a front view. A right side view, (d) is a plan view.
FIG. 7 is a circuit block diagram of a fuel cell system according to Embodiment 2 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) Reforming gas cooling heat exchanger (reforming 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

Claims (17)

A carbon monoxide remover that oxidizes and removes carbon monoxide in the reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst,
A heat insulating layer (32) covering the periphery of the catalyst layer (31) containing the catalyst, and a reformed gas cooling means (33) for cooling the reformed gas located on the upstream side of the catalyst layer (31),
Reformed gas cooling means (33), in a state where the temperature of the catalyst layer (31) is higher than the reaction starting temperature, the reformed gas flowing into the catalyst layer (31), the catalyst layer (31) A carbon monoxide remover configured to cool to a temperature at which the outlet temperature is lower than the side reaction generation temperature and to a temperature not higher than the reaction start temperature in the catalyst layer (31) . . The catalyst layer (31) is divided at an intermediate portion of the reformed gas flow path, and a second reformed gas cooling means (36) is provided at the divided portion . Carbon monoxide remover. The reformed gas cooling means (33, 36) is configured as a heat exchanger for recovering the heat of the reformed gas flowing into the catalyst layer (31) in a heat recovery medium. The carbon monoxide remover described. The carbon monoxide remover according to claim 3, wherein the reformed gas cooling means (33, 36) is a heat exchanger using fuel cell cooling water as a heat recovery medium from the reformed gas . The reformed gas cooling means (33, 36) is according to claim 3, characterized in that the heat transfer water to the exhaust heat is given of the fuel cell (10) is a heat exchanger for the heat recovery medium from the reformed gas The carbon monoxide remover described. The reformed gas cooling means (33, 36) 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 carbon monoxide remover according to claim 3 . The carbon monoxide remover according to claim 3, wherein the reformed gas cooling means (33, 36) is a heat exchanger using the exhaust gas of the fuel cell (10) as a heat recovery medium from the reformed gas. . The carbon monoxide removal according to any one of claims 1 to 7, wherein the reformed gas cooling means (33, 36) and the catalyst layer (31) are provided in an integral casing (35) . vessel. A fuel cell system comprising a carbon monoxide remover (30) for oxidizing and removing carbon monoxide in the reformed gas supplied to the fuel cell (10) in the presence of a carbon monoxide selective oxidation catalyst,
The carbon monoxide remover (30) is located on the upstream side of the catalyst layer (31) and the heat insulating layer (32) covering the periphery of the catalyst layer (31) containing the catalyst. Quality gas cooling means (33),
Reformed gas cooling means (33), in a state where the temperature of the catalyst layer (31) is higher than the reaction starting temperature, the reformed gas flowing into the catalyst layer (31), the catalyst layer (31) A fuel cell system configured to cool to a temperature at which an outlet temperature is lower than a side reaction generation temperature and to a temperature not higher than a reaction start temperature in the catalyst layer (31) . The catalyst layer (31) of the carbon monoxide remover (30) is divided at the middle portion of the reformed gas flow path, and the second reformed gas cooling means (36) is provided at the divided portion . The fuel cell system according to claim 9 . The reformed gas cooling means (33, 36) of the carbon monoxide remover (30) is configured as a heat exchanger that recovers the heat of the reformed gas flowing into the catalyst layer (31) to the heat recovery medium . The fuel cell system according to claim 9 or 10 . A fuel cell cooling water circuit in which fuel cell cooling water for cooling the fuel cell (10) circulates;
Carbon monoxide remover (30) reformed gas cooling means (33, 36) is according to claim 11, wherein the fuel cell cooling water is a heat exchanger to heat recovery medium from the reformed gas Fuel cell system. A heating water circuit through which heat transfer water to which the exhaust heat of the fuel cell (10) is given circulates is provided ,
Reformed gas cooling means carbon monoxide remover (30) (33, 36) is according to claim 11, wherein the a heat exchanger for the heat recovery medium from reformed gas the heat transfer water Fuel cell system. The reformed gas cooling means (33, 36) of the carbon monoxide remover (30) is heat that uses air or an oxygen-containing gas supplied to the oxygen electrode of the fuel cell (10) as a heat recovery medium from the reformed gas. The fuel cell system according to claim 11 , wherein the fuel cell system is an exchanger. Reformed gas cooling means carbon monoxide remover (30) (33, 36), a request, which is a heat exchanger for the exhaust gas of the fuel cell (10) and the heat recovery medium from the reformed gas Item 12. The fuel cell system according to Item 11 . The carbon monoxide remover (30) is characterized in that the reformed gas cooling means (33, 36) and the catalyst layer (31) are provided in an integral casing (35) . The fuel cell system according to any one of the above. Carbon monoxide remover reformed gas cooling means (33, 36) of (30), the reformed gas flowing into the catalyst layer (31), the temperature of the catalyst layer (31) after the system startup than the reaction starting temperature The fuel cell system according to any one of claims 9 to 16, wherein the fuel cell system is configured to start cooling after becoming high .

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