JP2008174447A - Operation control method of reforming apparatus for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation control method of a reforming apparatus for fuel cell by which an expensive CO sensor is made unnecessary, the estimation and guarantee of CO concentration are assured at the starting time, the deterioration of partial load efficiency is prevented, and the lowering of catalytic activity is also prevented. <P>SOLUTION: In the operation control method of a reforming apparatus, at the starting time, the operation control is carried out by estimating the reforming composition from the outlet temperature (Tc1) of a reforming part 2, the catalyst temperature (Tc2) of a CO shift part 5, and the catalyst temperature (Tc3) of a CO selective oxidation part 6, and thereby, a CO sensor conventionally used for the operation control at the starting time is made unnecessary. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention estimates a reforming composition based on an outlet temperature of a reforming section, a catalyst temperature of a shift section, and a catalyst temperature of a CO selective oxidation section in a fuel cell reforming apparatus equipped with a steam reformer for a fuel cell. The present invention relates to an operation control method for a fuel cell reforming apparatus that controls operation at startup.

When constructing a conventional power generation system using a polymer electrolyte fuel cell, the concentration of carbon monoxide in the fuel gas introduced into the polymer electrolyte fuel cell needs to be 10 ppm or less. On the other hand, when extracting hydrogen from hydrocarbons such as methane, carbon monoxide is produced as a by-product according to the following chemical formulas 1 and 2.

The composition in Chemical Formula 1 and Chemical Formula 2 is determined by the temperature equilibrium state, and CO is generally about 0.3 to 1%. Therefore, CO is reduced by chemical formula 3.

Although the final CO concentration is determined by the amount of CO produced in the above-mentioned chemical formulas 1 and _{2 and the} amount of O ₂ sucked in chemical formula 3, it is important to guarantee 10 ppm or less in an actual system.

  In the conventional first fuel cell power generation system (Japanese Patent Laid-Open No. 8-306378), detection by a CO sensor has been attempted.

  In the second conventional fuel cell power generation system (Japanese Patent Laid-Open No. 2000-67897), attempts have been made to stabilize the system by making the flow rate of reformed gas and the amount of oxygen sucked constant.

  The CO sensor in the first conventional fuel cell power generation system has a problem that it is expensive and particularly impractical because it is expensive in a hydrogen gas atmosphere.

  In addition, the conventional second fuel cell power generation system has a problem that the method for estimating and guaranteeing the CO concentration at start-up is uncertain and the partial load efficiency is deteriorated.

Further, in the above conventional fuel cell power generation system, when the oxidizer is blown in a state where the temperature of the selective oxidizer is low, hydrogen is combusted to condense the water produced and adhere to the catalyst surface, thereby hindering the catalytic activity. There was a problem.

  Therefore, the present inventor has proposed a reforming composition for a fuel cell comprising a steam reformer for a fuel cell, based on the outlet temperature of the reforming unit, the catalyst temperature of the shift unit, and the catalyst temperature of the CO selective oxidation unit. By focusing on the technical idea of the present invention to control the operation at the time of starting, and further research and development, an expensive CO sensor is unnecessary, and the CO concentration at the time of starting is estimated. The present invention has achieved the object of ensuring the guarantee and preventing the deterioration of the partial load efficiency and preventing the decrease of the catalyst activity.

An operation control method for a fuel cell reforming apparatus according to the present invention (first invention according to claim 1) is as follows:
A reforming section for reforming the reforming raw material, a shift section for shifting the gas emitted from the reforming section, and a CO selective oxidation for oxidizing the gas emitted from the shifting section using air as a CO oxidant. In the reformer for a fuel cell provided with a section,
By increasing the supply amount of water or steam prior to the reforming raw material when the load is increased, the operation at the time of load fluctuation is controlled.
The operation control method of the reformer for a fuel cell according to the present invention includes:
In a fuel cell reformer equipped with a steam reformer for a fuel cell,
The operation at startup is controlled by estimating the reforming composition based on the outlet temperature of the reforming unit, the catalyst temperature of the shift unit, and the catalyst temperature of the CO selective oxidation unit.

The operation control method of the reformer for a fuel cell according to the present invention includes:
In the present invention,
The operation at startup is controlled by controlling the amount of the CO oxidant supplied to the CO selective oxidation unit according to the catalyst temperature of the CO selective oxidation unit.

The operation control method of the reformer for a fuel cell according to the present invention includes:
In the present invention,
The operation at the normal time is controlled by maintaining the outlet temperature of the reforming unit within a certain range and controlling the amount of CO oxidant supplied to the CO selective oxidation unit according to the catalyst temperature of the shift unit. It is a thing.

The operation control method of the reformer for a fuel cell according to the present invention includes:
In the present invention,
The operation is controlled so that the outlet temperature of the reforming section is kept within a certain range when the load fluctuates.

The operation control method of the reformer for a fuel cell according to the present invention includes:
In the present invention,
When the load increases, the operation at the time of load fluctuation is controlled by increasing the supply amount of water or water vapor and the amount of CO oxidant supplied to the CO selective oxidation unit in advance. .

The operation control method of the reformer for a fuel cell according to the present invention includes:
In the present invention,
When the load decreases, the operation at the time of load change is controlled by decreasing the reforming raw material flow in advance.

The operation control method of the reformer for a fuel cell according to the first invention having the above-described configuration includes a reforming unit that reforms a reforming raw material, a shift unit that shift-reacts a gas emitted from the reforming unit, and the shift unit. In a fuel cell reformer equipped with a CO selective oxidation unit that oxidizes the gas emitted from the gas using air as a CO oxidant, the supply amount of water or water vapor is increased ahead of the reforming raw material when the load increases. As a result, the operation at the time of load fluctuation is controlled, so that an increase in CO concentration can be suppressed.
The operation control method for a fuel cell reforming apparatus of the present invention having the above-described configuration includes a reforming unit for a fuel cell having a steam reformer for a fuel cell, and an outlet temperature of the reforming unit and a catalyst temperature of the shift unit. Since the reforming composition is estimated based on the catalyst temperature of the CO selective oxidation unit and the operation at the time of start-up is controlled, there is an effect that an expensive CO sensor is unnecessary.

  The operation control method of the fuel cell reforming apparatus of the present invention having the above-described configuration is the first invention, wherein the amount of CO oxidant supplied to the CO selective oxidation unit is controlled according to the catalyst temperature of the CO selective oxidation unit As a result, since the operation at the time of startup is controlled, there is an effect of preventing moisture adhesion to the catalyst and a decrease in catalyst activity.

  The operation control method for a fuel cell reforming apparatus of the present invention having the above-described configuration is the second invention, wherein the outlet temperature of the reforming section is maintained within a certain range, and the CO in accordance with the catalyst temperature of the shift section. By controlling the amount of the CO oxidant supplied to the selective oxidation unit, the operation at the normal time is controlled, so that the operation control at the normal time is enabled.

  The operation control method for a fuel cell reforming apparatus of the present invention having the above-described configuration is such that, in the third aspect of the invention, the operation is controlled so that the outlet temperature of the reforming section is maintained within a certain range when the load fluctuates. Therefore, there is an effect that it is possible to suppress an increase in CO at the time of load fluctuation.

  The operation control method of the fuel cell reforming apparatus of the present invention having the above-described configuration is the fourth invention, wherein the load of water or steam and the CO oxidant supplied to the CO selective oxidation unit are increased when the load increases. Since the operation at the time of the load change is controlled by increasing the amount of the preceding, the effect of suppressing the increase of the CO at the time of the load change is exhibited.

  The operation control method of the fuel cell reforming apparatus of the present invention having the above-described configuration is the operation according to the fifth aspect, wherein when the load is reduced, the reforming raw material flow rate is reduced in advance to thereby reduce the operation at the time of load fluctuation. Since this is controlled, there is an effect of suppressing an increase in CO at the time of load fluctuation.

  Embodiments of the present invention will be described below with reference to the drawings.

  The operation control method for the fuel cell reforming apparatus of the first embodiment will be described below with reference to FIGS.

  As shown in FIG. 1, the reformer for a fuel cell according to the first embodiment has a temperature (Tc0) of an evaporator 3 as an evaporation section in a steam reformer, an outlet temperature (TC1) of a reforming section 2, CO 2 A means for detecting the catalyst temperature (Tc2) of the shift unit 5, the catalyst temperature (Tc3) of the CO selective oxidation unit 6, and the wall surface temperature (Tcw) of the reforming unit 2 is provided, and the following operation control method is used.

  At startup, the reforming composition is estimated from the outlet temperature (TC1) of the reforming unit 2, the catalyst temperature (Tc2) of the CO shift unit 5 and the catalyst temperature (Tc3) of the CO selective oxidation unit 6, The operation control is performed, and the conventional CO sensor in the operation control at the time of start-up is unnecessary.

  Further, it controls the supply amount of air as a CO oxidant to be supplied to the CO selective oxidation unit 6 according to the catalyst temperature (Tc3) of the CO selective oxidation unit 6 to reduce moisture adhesion to the catalyst and catalyst activity. (Deactivation) is prevented.

  In a steady state, the outlet temperature (TC1) of the reforming unit 2 is kept within a certain range, and is supplied to the CO selective oxidation unit 6 according to the catalyst temperature (Tc2) of the CO shift unit 5. By controlling the air flow rate of the (CO oxidizer), it is possible to control the operation in a steady state.

  When the load fluctuates, the outlet temperature (TC1) of the reforming unit 2 is maintained within a certain range, and when the load increases, the supply amount of water (steam) and the amount of oxidant are controlled in advance. When the load is reduced, the reforming raw material flow rate is controlled to decrease first.

In the steam reforming apparatus of the first embodiment, the reforming unit 2 performs chemical 1 (-Q ₁ : endothermic) and chemical 2 (+ Q ₂ : exothermic), the CO shift unit 5 performs chemical 2 and the CO selective oxidation. In Part 6, the reaction of Chemical Formula 3 (+ Q ₃ : exotherm) proceeds.

  Since the chemical formulas 1 and 2 are equilibrium reactions, the CO concentration and the composition of other chemical species are determined by the temperature of the reforming unit 2 and the temperature of the CO shift unit 5 under a constant pressure condition.

  When the reforming temperatures are 700 ° C. and 650 ° C., the theoretical change in the equilibrium CO concentration in the reformed gas accompanying the change in shift temperature is as follows. The reforming raw material was calculated by setting 13A gas for combustion and S / C = 3 indicating the ratio of the supply steam and the reforming raw material.

  As can be seen from FIG. 2 which shows the equilibrium concentration, the CO concentration strongly depends on the shift temperature. Although the dependence on the reforming unit 2 is also a level that cannot be ignored, the temperature of the reforming unit 2 can be controlled as shown in a specific example described later in actual operation. It is possible to estimate the CO temperature.

  In order to confirm these things, in the actual machine test, the temperature of the CO shift unit 5 was intentionally heated and cooled, and the equilibrium concentration and the experimental data were compared. The result shown in FIG. 3 was obtained. .

  The temperature in the vicinity of the catalyst outlet of the CO shift unit 5 is used as the temperature of the test data. Thus, a correlation was recognized between the equilibrium concentration and the actual machine data, and it was confirmed that the CO concentration could be estimated using the temperature of the shift catalyst.

  In FIG. 3 where comparison of the equilibrium value and experimental data is shown, the premise here is that a sufficient space (catalyst amount) is required for the amount of catalyst of the CO shift unit 5 to reach close to the equilibrium concentration.

When a copper / zinc based catalyst is used as the shift catalyst, it is confirmed that the CO concentration is reduced to near the equilibrium concentration if the SV value is (space velocity) 3500HR ⁻¹ in the unit test of the CO shift unit 5. However, considering the deterioration of the catalyst and the fact that the temperature conditions are not constant in the actual system, the fact that the catalyst activity differs from that of the unit test is taken into consideration. In the specific example described below, the CO shift unit is aimed at SV = 750. 5 was designed and manufactured.

  Further, if the flow rate is suddenly changed when the load fluctuates, the pressure fluctuation caused by the valve operation and the delay of the generated amount in the evaporation part are expected, and a deviation from the assumed equilibrium concentration is expected to occur at a certain moment.

  FIG. 4 shows the CO concentration at the outlet of the shift unit when the load of the reformer is varied from 50% to 100%. At this time, the flow rate of the reforming raw material (13A) and the reforming water were increased to the equivalent of 50% to 100% almost simultaneously. Further, the change in the CO concentration is recorded with a slight delay from the actual state due to measurement.

  In FIG. 4 showing the CO concentration when the load increases, it can be confirmed that the CO concentration in the reformed gas temporarily increases when the load fluctuates as expected. It is necessary to control the amount of oxidant in order to absorb such a fluctuation amount of CO by the CO selective oxidation unit 6, but when a CO sensor is not used as in the prior art, how much CO is at the time of load fluctuation. It is difficult to predict what will happen.

  Further, when CO is removed by oxidation, it is general to supply an oxidizing agent having an equivalent ratio of 3 or more. Therefore, when a large amount of CO is removed, a large amount of hydrogen is burned and a large amount of heat is generated. Since the CO selective oxidation catalyst has an activation temperature threshold, it is necessary to remove these heat generations. However, since the heat generation during load fluctuations is several times that in the steady state, a large cooling capacity is required.

  On the other hand, if the cooling is excessive during the steady state, the catalyst temperature may fall below the activity. Therefore, the cooling structure of the CO selective oxidation unit 6 requires cooling control in a wide range, resulting in a complicated system.

  By the way, the equilibrium composition determined in Chemical Formula 1 and Chemical Formula 2 depends on the amount of water vapor. Therefore, the equilibrium concentration when S / C was changed was calculated as shown in FIG. Thus, it can be seen that the CO concentration can be lowered by increasing the S / C.

  In FIG. 5 where the equilibrium concentration due to the amount of water vapor is shown, the reforming unit 2 has a temperature of 680 ° C., and the CO shift unit 5 has a temperature of 200 ° C.

Therefore, the following test was attempted.
(A) Increase the water supply amount (water vapor amount) ahead of the reforming raw material when the load fluctuates.
(B) Increase the oxidizing agent for CO selective oxidation after a time lag of T minutes, and immediately increase the reforming raw material flow rate.
By the above method, the CO concentration at the outlet of the CO shift unit 5 was examined for the time lag T = 1.5, 3, 5 minutes. In any case, an increase in CO concentration in the CO selective oxidation unit 6 was not observed.

  These results are shown in FIG. 6 when the time lag is 1.5 minutes, FIG. 7 when the time lag is 3 minutes, and FIG. 8 when the time lag is 5 minutes. Thus, by increasing the steam in advance of the reforming raw material, the increase in CO is suppressed when the load fluctuates, and the increase in the CO concentration at the outlet of the CO shift unit 5 in the case of a time lag of 3 minutes (FIG. 7) is little. I understand that there is no. That is, by setting T = 3 minutes, it was confirmed that the control of the CO selective oxidant flow rate works effectively using the map from the temperature Tc2 of the CO shift unit 5 which is one of the first embodiment.

  When considering a stationary power generation system, it is often not required to follow a steep load change, so if there is a load change capability within 3 minutes, it is considered that there is no practical problem.

  Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

  The operation control method of the fuel cell reforming apparatus of the second embodiment will be described below with reference to FIGS. 1, 9, 11 to 15. FIG.

  The steam reformer for natural gas of Example 2 includes a combustion burner 1, a reforming unit 2 using a ruthenium catalyst, an evaporator 3, a heat exchanger 4, copper, as illustrated in FIG. A CO shift unit 5 using a zinc-based catalyst and a CO selective oxidation unit 6 using a ruthenium catalyst.

  Natural gas (13A main component methane) serving as a reforming raw material is mixed with steam generated in the evaporation section 3 and preheated to about 500 ° C. in the heat exchanger 4 and then introduced into the reforming section 2. Then, while being heated in the combustion burner 1, a shift main reaction, which is mainly the reforming main reaction shown by Chemical Formula 1 and the side reaction shown by Chemical Formula 2, is caused.

  At this time, the combustion amount of the combustion burner 1 is adjusted so that the reformed gas outlet temperature is about 650 ° C. (Te). The gas exiting the reforming section 2 exchanges heat with the raw material gas in the heat exchanger 4, and after being cooled to about 170 to 250 ° C., the shift reaction indicated by the chemical formula 2 is caused in the CO shift section 5. .

  After this CO shift, the CO concentration is reduced to 1% or less depending on the temperature. In the PEFC type fuel cell 7, since CO poisoning of the electrode occurs, the CO concentration in the fuel gas introduced into the PEFC needs to be lowered to 10 ppm or less. Therefore, after the shift reaction, the CO selective oxidation unit 6 composed of a ruthenium catalyst is provided, and CO is reduced to 10 ppm or less by an oxidation reaction indicated by the reformed gas 2 using air as an oxidant.

The amount of oxidized air at this time is determined and controlled from the temperature Tc2 of the CO shift unit 5 and the reformed gas flow rate. In the control, a map (air flow rate = function (Tc2, reforming raw material flow rate)) obtained from experiments and calculations was used.
The details of the operation method during startup, steady state, and load fluctuation will be described below.

  The operation procedure at the time of startup is performed according to the flowchart shown in FIG. That is, FIG. 3 shows the result when the reforming unit is started according to the operation sequence shown in FIG.

  When the temperature of the evaporating unit 3 reaches a predetermined temperature after the burner 1 is ignited, water supply is started and water vapor is spread throughout the reformer 2. Thereafter, the reforming raw material is charged and reforming is started. When the temperature of the reforming unit 2 reaches a predetermined temperature, the reforming unit 2 is considered to be activated.

  The CO shift unit 5 is considered to be complete when the catalyst reaches the activation temperature. A heater may be used to shorten the time required to reach the activation temperature. With respect to the CO selective oxidation unit 6, after the reforming starts, the temperature starts to rise after the reformed gas begins to flow.

  The input amount of air for CO removal is determined from the temperature of the CO selective oxidation unit 6 according to a map prepared in advance for activation. This map is determined from the reforming raw material flow rate and the temperature of the CO selective oxidation unit 6, and does not refer to the temperature Tc2 of the CO shift unit 5.

  After the catalyst temperature of the CO selective oxidation unit 6 reaches the lower limit of activity, if the catalyst temperature is within an appropriate range after being held for a certain period of time, the CO selective oxidation unit 6 is considered to have been started. When the reforming unit 2, the CO shift unit 5, and the CO selective oxidation unit 6 are all in place and the start-up completion condition is satisfied, the start-up of the reformer is completed, and hydrogen can be supplied to the fuel cell stack.

  When starting and stopping are frequently performed and the reforming unit 2 is started in a warm state, the temperature indication of the CO selective oxidation unit 6 may be high from the beginning. However, the temperature distribution of the selective oxidation unit 6 during the natural heat radiation during the stop varies, and there is a portion where the temperature is low. In this case, even if the temperature is instructed to be a high value immediately after the oxidation air is supplied, moisture condensation occurs at a low temperature portion, and the temperature of the entire catalyst may decrease after a while. By performing the activity determination after holding for a certain period of time, it is possible to avoid problems due to the above situation.

In addition, in the second embodiment, the following two types of maps were used as the map of the selective oxidation air flow rate. T311 is the lower limit temperature of the selective oxidation catalyst, and Ta is the selective oxidation air charging start temperature. FIG. 10A shows the result of starting using the map 2 shown in Table 2. In Map 2, when Tc3 reaches Ta, a somewhat larger flow rate is input. When the catalyst temperature reaches the lower limit of activity, reduce the flow rate and change it to the flow rate set at startup.

On the other hand, in the map 1 shown in Table 1, the flow rate is finely controlled by dividing into four until reaching the final flow rate when the startup is completed. The result using Map 1 is shown in FIG. Although there is no significant difference between the map 2 and the start-up time until the CO is reduced, in an environment where water condensation is likely to occur in the selective oxidation section, such as in winter, the oxidation air is reduced as observed in the figure. It can be seen that immediately after the addition, the water produced by the combustion of hydrogen is condensed, and the temperature of the selective oxidation section is lowered. In such a case, the map 1 that does not blow a large amount of oxidant at a time can obtain better results.

  On the other hand, since it is easy to change to the control of map 2 by changing the data of map 1, the system adopts the control method associated with map 1 and the data content according to map 2 as necessary. If the map is called and controlled, both can be controlled without major changes.

  The operation procedure at regular time is performed according to the flowchart shown in FIG. The flow rate of the oxidizing air and the amount of natural gas 13A that is a reforming raw material burned in the burner 1 are always controlled.

  Any of the temperature Tc1 of the reforming unit 2, the temperature Tc2 of the CO shift unit 5, the temperature Tc3 of the CO selective oxidation unit 6, and the wall surface temperature Tcw of the reforming unit 2 is outside the allowable temperature range. If this is the case, stop generating electricity immediately.

  The CO selective oxidation unit 6 is supplied with an oxidizing agent having a flow rate determined from the reforming raw material flow rate and the map data of the temperature Tc2 of the CO shift unit 5.

The operation procedure when the load is increased is performed according to the flowchart when the load is increased as shown in FIG.
The flow rate of oxidizing air and the amount of natural gas 13A that is a reforming raw material burned by the burner 1 are always controlled.

  Any of the temperature Tc1 of the reforming unit 2, the temperature Tc2 of the CO shift unit 5, the temperature Tc3 of the CO selective oxidation unit 6, and the wall surface temperature Tcw of the reforming unit 2 is outside the allowable temperature range. If this is the case, stop generating electricity immediately.

  Three minutes after the water supply amount (water vapor amount) is increased to a predetermined flow rate, the oxidant flow rate to the CO selective oxidation unit 6 is increased, and immediately the reforming raw material flow rate is increased.

The operation procedure at the time of load reduction is performed according to the flowchart at the time of load reduction shown in FIG.
The flow rate of oxidizing air and the amount of natural gas 13A that is a reforming raw material burned by the burner 1 are always controlled.

  Any of the temperature Tc1 of the reforming unit 2, the temperature Tc2 of the CO shift unit 5, the temperature Tc3 of the CO selective oxidation unit 6, and the wall surface temperature Tcw of the reforming unit 2 is outside the allowable temperature range. If this is the case, stop generating electricity immediately.

  Immediately after reducing the reforming raw material, the water supply amount (water vapor amount) and the air flow rate of the oxidizing agent supplied to the CO selective oxidation unit 6 are reduced.

When the load was reduced, even if the steam and the reforming raw material were simultaneously reduced, the increase in CO did not occur as is apparent from FIG. 15 showing the change in CO concentration when the load was reduced.

  The above-described embodiments have been illustrated for the purpose of explanation, and the present invention is not limited thereto. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the description of the drawings. Modifications and additions can be made without departing from the technical idea of the present invention.

  A reforming unit for reforming the reforming raw material, a shift unit for shifting the gas emitted from the reforming unit, and a CO selective oxidation unit for oxidizing the gas output from the shift unit using a CO oxidant. In the reformer for a fuel cell, by estimating the CO concentration in the reformed gas based on the outlet temperature of the reforming unit, the catalyst temperature of the shift unit, and the catalyst temperature of the CO selective oxidation unit, As an operation control, the supply amount of air as a CO oxidant supplied to the CO selective oxidation unit is controlled. The present invention can be applied to applications that make it possible to reliably estimate the CO concentration in the reformed gas and eliminate the need for an expensive CO sensor.

It is a block diagram which shows the natural gas fuel cell system of Example 1 and Example 2 of this invention. It is a diagram which shows the shift temperature in this Example 1, and the equilibrium density | concentration of CO density | concentration. It is a diagram which shows the relationship between the equilibrium calculated value in this Example 1, and experimental data. It is a diagram which shows CO density | concentration at the time of load increase in the present Example 1. FIG. It is a diagram which shows the equilibrium density | concentration by the influence of the water vapor amount in the present Example 1. FIG. It is a diagram which shows the change of CO density | concentration in case the time lag in this Example 1 is 1.5 minutes. It is a diagram which shows the change of CO concentration in the case of the time lag 3 minutes in a present Example 1. FIG. It is a diagram which shows the change of CO concentration in the case of the time lag 5 minutes in a present Example 1. FIG. It is a chart figure which shows the procedure of the reformer operation sequence in the present Example 2. It is a diagram which shows the change of CO concentration at the time of starting according to the maps 1 and 2 in a present Example 2, respectively. It is a chart figure which shows the driving | operation procedure at the time of starting in the present Example 2. It is a chart figure which shows the driving | operation procedure at the time of the steady driving | operation in the present Example 2. FIG. It is a chart figure which shows the driving | operation procedure at the time of the load increase in the present Example 2. It is a chart figure which shows the driving | operation procedure at the time of load reduction in the present Example 2. It is a diagram which shows the change of CO concentration when the water vapor | steam at the time of load reduction in this Example 2 and a reforming raw material are reduced.

Explanation of symbols

2 reforming section 5 CO shift section 6 CO selective oxidation section

Claims (1)

A reforming section for reforming the reforming raw material, a shift section for shifting the gas emitted from the reforming section, and a CO selective oxidation for oxidizing the gas emitted from the shifting section using air as a CO oxidant. In the reformer for a fuel cell provided with a section,
An operation control method for a reformer for a fuel cell, characterized in that the operation at the time of load fluctuation is controlled by increasing the supply amount of water or steam before the reforming raw material when the load increases.

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