JP2023071203A - Solid oxide fuel cell system - Google Patents

Abstract

To provide an SOFC system capable of suppressing variations in a power generation amount by independently controlling a temperature of a reformer and a temperature of a stack.SOLUTION: An SOFC system 1 comprises a stack 2, a reformer 3, a combustor 4, a fuel gas adjustment valve 13, an air blower 11, an anode off-gas path 37 that branches to a recycle path 36 and a combustor path 35, an anode off-gas blower 16 provided on the anode off-gas path, a reformer temperature sensor 42 for detecting a catalyst temperature of the reformer, and a stack temperature sensor 41 for detecting a stack temperature. The air blower adjusts a flow rate of air 31 on the basis of the stack temperature. The anode off-gas blower adjusts a distribution ratio between an anode off-gas flowing through the recycle path and the anode off-gas flowing through the combustor path on the basis of the catalyst temperature. The fuel gas adjustment valve adjusts a flow rate of a fuel gas 33 on the basis of the catalyst temperature.SELECTED DRAWING: Figure 1

Description

The present application relates to solid oxide fuel cell systems.

A solid oxide fuel cell (hereinafter also referred to as SOFC) uses a solid oxide electrolyte with high ion conductivity such as yttria-stabilized zirconium as a fuel electrode (hereinafter referred to as an anode) and an air electrode (hereinafter referred to as an anode). hereinafter referred to as a cathode). A single cell is a device in which an electrolyte is sandwiched between an anode and a cathode. An anode gas such as hydrogen or carbon monoxide is supplied to the anode, and a cathode gas such as air containing oxygen is supplied to the cathode. City gas or the like containing methane as a main component is used as the fuel gas that is the raw material for the anode gas.

The SOFC system that drives the SOFC includes a reformer that reforms fuel gas such as city gas into anode gas, which is a mixed gas of hydrogen and carbon monoxide, and a combustor that heats the catalyst of the reformer. and This SOFC system may be provided with a recycling path for reusing the anode off-gas discharged from the anode as fuel gas and a combustor path for using the anode off-gas as combustion gas for the combustor. In such an SOFC system, there is a problem that the reforming rate drops significantly when the temperature of the reformer drops. To address this problem, conventional SOFC systems detect the temperature of the reformer and control the distribution of the anode off-gas flowing through the recycling path and the anode off-gas flowing through the combustor path according to the temperature of the reformer. A method is disclosed (see, for example, Patent Document 1).

JP 2009-76273 A

When the temperature of the reformer drops and the reforming rate drops, the amount of anode gas also drops, so the temperature of the stack drops and the amount of power generated by the SOFC drops. In conventional SOFC systems, control is performed by detecting only the temperature of the reformer. Therefore, the reforming rate does not increase until the temperature of the combustor is increased by increasing the anode off-gas flowing through the combustor path in order to raise the temperature of the reformer. Then, the SOFC stack temperature continues to decrease unless the reforming rate of the reformer increases. That is, in the conventional SOFC system, the temperature of the reformer and the temperature of the stack could not be controlled independently. Therefore, there is a problem that the amount of power generated by the SOFC fluctuates greatly.

The present application has been made to solve the above-mentioned problems, and aims to provide an SOFC system capable of suppressing fluctuations in the power generation amount by independently controlling the temperature of the reformer and the temperature of the stack. aim.

The solid oxide fuel cell system of the present application comprises a stack comprising an anode, an electrolyte and a cathode, a reformer for reacting a fuel gas with water vapor to produce an anode gas containing hydrogen, and a catalyst for the reformer. A combustor for generating combustion gas for heating, a fuel gas regulating valve for regulating the flow rate of the fuel gas for supplying the anode gas to the anode, and an air blower for regulating the flow rate of the air supplied to the cathode. an anode off-gas path branched into a recycling path for supplying the anode off-gas discharged from the anode to the reformer and a combustor path for supplying the anode off-gas to the combustor; and an anode provided in the anode off-gas path and flowing through the recycling path. An anode offgas blower that adjusts the distribution ratio between the offgas and the anode offgas flowing through the combustor path, a reformer temperature sensor that detects the temperature of the reformer catalyst, and a stack temperature sensor that detects the stack temperature. I have it. The air blower adjusts the flow rate of air supplied to the cathode based on the stack temperature detected by the stack temperature sensor, and the anode off-gas blower adjusts the catalyst temperature detected by the reformer temperature sensor. The fuel gas adjustment valve adjusts the fuel gas flow rate based on the temperature of the catalyst detected by the reformer temperature sensor. are adjusting.

Another solid oxide fuel cell system of the present application includes a stack comprising an anode, an electrolyte and a cathode; a reformer for reacting a fuel gas with water vapor to produce an anode gas containing hydrogen; A combustor that generates combustion gas for heating the catalyst of the vessel, a fuel gas control valve that adjusts the flow rate of the fuel gas to supply the anode gas to the anode, and a flow rate of the air that is supplied to the cathode. a blower for air; an anode offgas path branched into a recycling path for supplying the anode offgas discharged from the anode to the reformer; and a combustor path for supplying the anode offgas to the combustor; An anode offgas blower that adjusts the distribution ratio between the anode offgas flowing through the path and the anode offgas flowing through the combustor path, a combustor temperature sensor that detects the temperature of the combustion gas in the combustor, and a stack temperature that detects the stack temperature. and a sensor. The air blower adjusts the flow rate of air supplied to the cathode based on the stack temperature detected by the stack temperature sensor, and the anode off-gas blower adjusts the combustion gas temperature detected by the combustor temperature sensor. The fuel gas adjustment valve adjusts the fuel gas flow rate based on the combustion gas temperature detected by the combustor temperature sensor. are adjusting.

In the solid oxide fuel cell system of the present application, the air blower adjusts the flow rate of air supplied to the cathode based on the stack temperature detected by the stack temperature sensor, and the anode offgas blower adjusts the reformer temperature. Based on the temperature of the catalyst detected by the sensor, the distribution ratio of the anode off-gas flowing through the recycle path and the anode off-gas flowing through the combustor path is adjusted, and the fuel gas adjustment valve detects the temperature of the catalyst detected by the reformer temperature sensor. Since the flow rate of the fuel gas is adjusted based on the above, it is possible to control the temperature of the reformer and the temperature of the stack independently, thereby suppressing fluctuations in the power generation amount.

In another solid oxide fuel cell system of the present application, the air blower adjusts the flow rate of the air supplied to the cathode based on the temperature of the stack detected by the stack temperature sensor, and the anode offgas blower burns. The fuel gas control valve adjusts the distribution ratio between the anode off-gas flowing through the recycling path and the anode off-gas flowing through the combustor path based on the temperature of the combustion gas detected by the combustor temperature sensor, and the combustion detected by the combustor temperature sensor. Since the flow rate of the fuel gas is adjusted based on the gas temperature, it is possible to independently control the temperature of the reformer and the temperature of the stack, thereby suppressing fluctuations in the power generation amount.

1 is a configuration diagram of a solid oxide fuel cell system according to Embodiment 1; FIG. FIG. 2 is a configuration diagram of a solid oxide fuel cell system according to Embodiment 2; FIG. 10 is a configuration diagram of a solid oxide fuel cell system according to Embodiment 3;

Hereinafter, solid oxide fuel cell systems according to embodiments for carrying out the present application will be described in detail with reference to the drawings. In each figure, the same reference numerals denote the same or corresponding parts.

Embodiment 1.
FIG. 1 is a configuration diagram of a solid oxide fuel cell system according to Embodiment 1. FIG. A solid oxide fuel cell system 1 according to this embodiment has a stack 2 , a reformer 3 , a combustor 4 and a desulfurizer 5 . The stack 2 is configured by laminating an electrolyte 23 between a cathode 21 and an anode 22 . The solid oxide fuel cell system 1 is supplied with air 31 , pure water 32 and fuel gas 33 as raw materials. Air 31 is supplied as cathode gas to the cathode 21 via the air blower 11 . The pure water 32 is heated in the heat exchanger 12 by heat exchange with an anode off-gas, which will be described later, and converted into water vapor. The steam converted by the heat exchanger 12 is supplied to the fuel gas sent from the desulfurizer 5 to the reformer 3 via the steam supply path 34 . The fuel gas 33 is sent to the desulfurizer 5 via the fuel gas regulating valve 13 . The desulfurizer 5 removes sulfur components from fuel gas containing sulfur components such as city gas. The fuel gas from which sulfur components have been removed by the desulfurizer 5 is sent to the reformer 3 . The reformer 3 is provided with a catalyst and the like inside. The reformer 3 performs a reforming reaction using the fuel gas supplied from the desulfurizer 5 and the steam supplied from the steam supply path 34 as raw materials to generate an anode gas containing a large amount of hydrogen and carbon monoxide. do. Anode gas generated in the reformer 3 is supplied to the anode 22 . Note that the desulfurizer 5 may be omitted when fuel gas containing no sulfur component such as methane is used.

A load 50 is connected to the stack 2 . In the stack 2, an electrochemical reaction takes place in a temperature environment of 600-1000.degree. The oxygen supplied to the cathode 21 receives electrons, becomes oxygen ions, and is transported to the electrolyte 23 . The hydrogen supplied to the anode 22 emits electrons to become hydrogen ions, which combine with oxygen ions that have passed through the electrolyte 23 to produce water. The carbon monoxide supplied to the anode 22 emits electrons to become carbon monoxide ions, which combine with oxygen ions that have passed through the electrolyte 23 to produce carbon dioxide. Electrons emitted from the anode 22 reach the cathode 21 via the load 50 . Electricity is generated in the stack 2 by such an electrochemical reaction.

The air 31, which is the cathode gas, is discharged from the stack 2 as cathode off-gas after being consumed at the cathode 21. FIG. The anode gas is exhausted from the stack 2 as anode off-gas after being consumed at the anode 22 . Cathode off-gas is sent to combustor 4 . The anode off-gas is heat-exchanged with the pure water 32 in the heat exchanger 12, and then cooled in the heat exchanger 14 and the condenser 15 to below the heat-resistant temperature of the anode off-gas blower 16, which will be described later. The anode off-gas that has passed through the condenser 15 flows through a combustor path 35 connected to the combustor 4 and a recycling path 36 connected to the fuel gas path. A path branched into the combustor path 35 and the recycling path 36 is referred to as an anode offgas path 37 . The anode offgas blower 16 and the heat exchanger 14 are connected to the recycle path 36 . The anode off-gas blower 16 can adjust the distribution ratio between the anode off-gas flowing through the combustor path 35 and the anode off-gas flowing through the recycling path 36 . The heat exchanger 14 heats the anode off-gas flowing through the recycling route 36 by exchanging heat between the anode off-gas flowing through the recycling route 36 and the upstream anode off-gas.

The combustor 4 combusts the cathode off-gas and the anode off-gas sent via the combustor path 35 to generate high-temperature combustion gas. The catalyst of the reformer 3 is heated by the combustion gas produced by the combustor 4 . Combustion gas is sent to the heat exchanger 17 via the reformer 3 . The heat exchanger 17 exchanges heat between the air sent from the air blower 11 to the cathode 21 and the combustion gas to increase the temperature of the air sent to the cathode 21 . The combustion gas that has undergone heat exchange in the heat exchanger 17 is discharged to the outside. Ignition of the combustor 4 is performed by an ignition transformer installed inside the combustor 4 .

The stack 2 and the reformer 3 are provided with a stack temperature sensor 41 and a reformer temperature sensor 42, respectively. A stack temperature sensor 41 detects the temperature of the stack 2 . The reformer temperature sensor 42 detects the temperature of the catalyst of the reformer 3 .

The air blower 11 is controlled by an air blower controller 44 . The fuel gas regulating valve 13 is controlled by a fuel gas regulating valve controller 45 . The anode offgas blower 16 is controlled by an anode offgas blower controller 46 . The air blower controller 44 uses the air blower 11 to control the amount of air supplied based on the stack temperature measured by the stack temperature sensor 41 . The fuel gas regulating valve controller 45 uses the fuel gas regulating valve 13 to control the supply amount of fuel gas based on the temperature of the catalyst of the reformer 3 measured by the reformer temperature sensor 42 . The anode offgas blower controller 46 uses the anode offgas blower 16 based on the temperature of the catalyst of the reformer 3 measured by the reformer temperature sensor 42 to flow the anode offgas flowing through the combustor path 35 and the recycling path 36 . It controls the distribution ratio with the anode off-gas.

The condenser 15 adjusts the amount of water contained in the anode offgas. The condenser 15 condenses part of the water vapor contained in the anode off-gas to produce condensed water. Water vapor that is not condensed in the condenser 15 is sent to the reformer 3 through the recycling path 36 together with the anode off-gas. The anode off-gas is cooled by the heat exchanger 12, the heat exchanger 14 and the condenser 15 to a temperature not higher than the heat-resistant temperature of the anode off-gas blower 16 (for example, up to 80°C). Note that the condensed water generated by the condenser 15 may be converted into steam by the heat exchanger 12 and this steam may be supplied to the steam supply path 34 .

Next, the operation of the solid oxide fuel cell system 1 in this embodiment will be described.
The fuel gas regulating valve controller 45 adjusts the fuel gas regulating valve 13 to supply the fuel gas 33 necessary for power generation. The fuel gas 33 is desulfurized by the desulfurizer 5 and sent to the reformer 3 . Steam is supplied to the reformer 3 from the pure water 32 via the steam supply path 34 . The reformer 3 reforms the supplied fuel gas and steam to generate an anode gas containing a large amount of hydrogen, and supplies this anode gas to the anode 22 . The air blower controller 44 adjusts the air blower 11 to supply the cathode 21 with the air 31 required for power generation. In the stack 2, oxygen contained in the air and hydrogen and carbon monoxide contained in the anode gas undergo oxidation-reduction reaction to generate electrons, which move to the load 50 and are consumed as electric power.

After passing through the anode 22, the anode gas becomes an anode off-gas. The anode off-gas is cooled in heat exchangers 12 and 14 and condenser 15 . The anode offgas blower controller 46 adjusts the anode offgas blower 16 to control the distribution ratio between the anode offgas flowing through the combustor path 35 and the anode offgas flowing through the recycling path 36 .

In the solid oxide fuel cell system 1 operating in this way, the operation when the temperature of the catalyst of the reformer 3 drops from the optimum temperature will be described.
The temperature sensor 42 for the reformer detects a decrease in the temperature of the catalyst of the reformer 3 . When the reformer temperature sensor 42 detects a decrease in catalyst temperature, the anode offgas blower controller 46 adjusts the anode offgas blower 16 to increase the distribution ratio of the anode offgas flowing through the combustor path 35 . In the combustor 4 , the temperature of the combustion gas rises due to the increase in the anode off-gas supplied from the combustor path 35 . An increase in the temperature of the combustion gas also increases the temperature of the catalyst. However, the distribution ratio of the anode off-gas flowing through the recycling path 36 decreases. Therefore, the anode off-gas supplied to the reformer 3 via the recycling path 36 is reduced. As a result, the amount of anode gas supplied from the reformer 3 to the anode 22 may decrease.

In the solid oxide fuel cell system 1 of the present embodiment, when the reformer temperature sensor 42 detects a decrease in catalyst temperature, the fuel gas regulating valve controller 45 adjusts the fuel gas regulating valve 13. to increase the amount of fuel gas supplied. Therefore, even when the amount of anode off-gas supplied to the reformer 3 via the recycling path 36 decreases, the amount of anode gas can be suppressed from decreasing.

Thereafter, when the reformer temperature sensor 42 detects an increase in catalyst temperature, the anode offgas blower controller 46 adjusts the anode offgas blower 16 to reduce the distribution ratio of the anode offgas flowing through the combustor path 35. At the same time, the fuel gas regulating valve controller 45 adjusts the fuel gas regulating valve 13 to reduce the amount of fuel gas supplied. In this way, the amount of anode gas supplied from the reformer 3 to the anode 22 can be kept constant.

In such a solid oxide fuel cell system 1, even if the temperature of the catalyst in the reformer 3 drops, the amount of anode gas can be kept constant. However, the anode gas may decrease, albeit temporarily. As the amount of anode gas decreases, the amount of power generated decreases, and the amount of air that is not consumed in the electrochemical reaction with the anode gas increases, resulting in a decrease in the temperature of the stack 2 . In a conventional solid oxide fuel cell system, when the temperature of the stack drops, the amount of electricity generated by the stack continues to drop unless the temperature of the reformer catalyst rises. As a result, fluctuations in the power generation amount of the stack increase.

Next, in the solid oxide fuel cell system 1 of the present embodiment, the case where the stack temperature sensor 41 detects a drop in the temperature of the stack 2 will be described.
When the stack temperature sensor 41 detects a drop in the temperature of the stack 2 , the air blower controller 44 adjusts the air blower 11 to reduce the amount of air supplied to the cathode 21 . As a result, the amount of air supplied to the cathode 21 decreases and the temperature of the stack 2 rises. After that, when the stack temperature sensor 41 detects an increase in the temperature of the stack 2 , the air blower controller 44 adjusts the air blower 11 to increase the amount of air supplied to the cathode 21 . In this way the temperature of the stack 2 can be kept constant.

In the solid oxide fuel cell system 1 configured as described above, when the temperature of the reformer 3 drops, the temperature of the reformer 3 is kept constant by the anode offgas blower controller 46 and the fuel gas regulating valve controller 45. When the temperature of the stack 2 drops, the air blower controller 44 can perform control to keep the temperature of the stack 2 constant. Therefore, in the solid oxide fuel cell system of the present embodiment, it is possible to independently control the temperature of the reformer and the temperature of the stack, thereby suppressing fluctuations in power generation.

In addition, in the solid oxide fuel cell system of the present embodiment, the anode offgas blower 16 is provided in the recycling path 36 , but may be provided in the combustor path 35 .

Embodiment 2.
In the solid oxide fuel cell system according to Embodiment 1, the temperature of the reformer catalyst is detected by the reformer temperature sensor. The catalyst of the reformer is heated by the combustion gas produced by the combustor. Therefore, the temperature of the reformer catalyst is affected by the temperature of the combustion gas. In the solid oxide fuel cell system according to Embodiment 2, instead of detecting the temperature of the catalyst, the temperature of the combustion gas is detected and controlled.

FIG. 2 is a configuration diagram of a solid oxide fuel cell system according to this embodiment. The solid oxide fuel cell system 1 according to the present embodiment includes a combustor temperature sensor 43 in place of the reformer temperature sensor in the solid oxide fuel cell system of the first embodiment. The combustor temperature sensor 43 detects the temperature of combustion gas generated in the combustor 4 . The fuel gas regulating valve controller 45 uses the fuel gas regulating valve 13 to control the supply amount of fuel gas based on the temperature of the combustion gas measured by the combustor temperature sensor 43 . The anode offgas blower controller 46 uses the anode offgas blower 16 to distribute the anode offgas flowing through the combustor path 35 and the anode offgas flowing through the recycling path 36 based on the temperature of the combustion gas measured by the combustor temperature sensor 43 . Control the ratio.

In the solid oxide fuel cell system 1 operating in this way, the operation when the temperature of the combustion gas in the combustor 4 drops from the optimum temperature will be described. When the temperature of the combustion gas drops from the optimum temperature, the temperature of the catalyst of the reformer 3 also drops from the optimum temperature.
A decrease in the temperature of the combustion gas in the combustor 4 is detected by the combustor temperature sensor 43 . When the combustor temperature sensor 43 detects a decrease in the temperature of the combustion gas, the anode offgas blower controller 46 adjusts the anode offgas blower 16 to increase the distribution ratio of the anode offgas flowing through the combustor path 35. In the combustor 4 , the temperature of the combustion gas rises due to the increase in the anode off-gas supplied from the combustor path 35 . An increase in the temperature of the combustion gas also increases the temperature of the catalyst. However, the distribution ratio of the anode off-gas flowing through the recycling path 36 decreases. Therefore, the anode off-gas supplied to the reformer 3 via the recycling path 36 is reduced. As a result, the amount of anode gas supplied from the reformer 3 to the anode 22 may decrease.

In the solid oxide fuel cell system 1 of the present embodiment, when the combustor temperature sensor 43 detects a decrease in the temperature of the combustion gas, the fuel gas regulating valve controller 45 adjusts the fuel gas regulating valve 13. to increase the amount of fuel gas supplied. Therefore, even when the amount of anode off-gas supplied to the reformer 3 via the recycling path 36 decreases, the amount of anode gas can be suppressed from decreasing.

Thereafter, when the combustor temperature sensor 43 detects an increase in the temperature of the combustion gas, the anode offgas blower controller 46 adjusts the anode offgas blower 16 to reduce the distribution ratio of the anode offgas flowing through the combustor path 35. At the same time, the fuel gas regulating valve controller 45 adjusts the fuel gas regulating valve 13 to reduce the amount of fuel gas supplied. In this way, the amount of anode gas supplied from the reformer 3 to the anode 22 can be kept constant.

In such a solid oxide fuel cell system 1, the amount of anode gas can be kept constant even if the temperature of the combustion gas drops. However, the anode gas may decrease, albeit temporarily. As the amount of anode gas decreases, the amount of power generated decreases, and the amount of air that is not consumed in the electrochemical reaction with the anode gas increases, resulting in a decrease in the temperature of the stack 2 . In a conventional solid oxide fuel cell system, when the temperature of the stack drops, the amount of electricity generated by the stack continues to drop unless the temperature of the combustion gas rises. As a result, fluctuations in the power generation amount of the stack increase.

Next, in the solid oxide fuel cell system 1 of the present embodiment, the case where the stack temperature sensor 41 detects a drop in the temperature of the stack 2 will be described.
When the stack temperature sensor 41 detects a drop in the temperature of the stack 2 , the air blower controller 44 adjusts the air blower 11 to reduce the amount of air supplied to the cathode 21 . As a result, the amount of air supplied to the cathode 21 decreases and the temperature of the stack 2 rises. After that, when the stack temperature sensor 41 detects an increase in the temperature of the stack 2 , the air blower controller 44 adjusts the air blower 11 to increase the amount of air supplied to the cathode 21 . In this way the temperature of the stack 2 can be kept constant.

In the solid oxide fuel cell system 1 configured as described above, when the temperature of the combustion gas drops, the anode offgas blower controller 46 and the fuel gas regulating valve controller 45 perform control to keep the temperature of the combustion gas constant. When the temperature of the stack 2 drops, the blower controller 44 for air can perform control to keep the temperature of the stack 2 constant. Therefore, in the solid oxide fuel cell system of the present embodiment, as in the first embodiment, the temperature of the reformer and the temperature of the stack can be controlled independently, thereby suppressing fluctuations in the power generation amount. can do.

Embodiment 3.
FIG. 3 is a configuration diagram of a solid oxide fuel cell system according to Embodiment 3. FIG. In the solid oxide fuel cell system 1 according to the present embodiment, a stack voltage sensor 47 for detecting the voltage of the stack 2 is added to the solid oxide fuel cell system according to the first embodiment. A stack voltage detected by the stack voltage sensor 47 is sent to the fuel gas regulating valve controller 45 . Other configurations of the solid oxide fuel cell system 1 of the present embodiment are the same as those of the solid oxide fuel cell system of the first embodiment.

In the solid oxide fuel cell system 1 of the present embodiment, the stack voltage is detected by the stack voltage sensor 47, and the anode gas supplied to the stack 2 is adjusted according to the change in the stack voltage. For example, at the start of operation, the fuel gas adjusting valve controller 45 adjusts the fuel gas adjusting valve 13 so that the temperature of the stack 2 is 600°C. When the stack voltage drops due to deterioration over time, the fuel gas regulating valve controller 45 adjusts the fuel gas regulating valve 13 to increase the anode gas sent to the stack 2 and reduce the fuel utilization rate in the stack 2 . By lowering the fuel utilization rate in the stack 2, the load applied to the stack can be reduced.

In the solid oxide fuel cell system 1 configured in this way, fluctuations in the power generation amount can be suppressed in the same manner as in the first embodiment, and progress of aged deterioration of the stack can be prevented by monitoring the stack voltage. can be suppressed.

The configuration of the solid oxide fuel cell system of the present embodiment is the same as that of the solid oxide fuel cell system of the first embodiment except that a stack voltage sensor 47 for detecting the voltage of the stack 2 is added. be. Alternatively, a configuration in which the stack voltage sensor 47 is added to the configuration of the solid oxide fuel cell system of the second embodiment may be used. In the solid oxide fuel cell system configured in this way, it is also possible to suppress fluctuations in the power generation amount, and to suppress progress of aged deterioration of the stack by monitoring the stack voltage.

While this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may apply to particular embodiment applications. The embodiments are applicable singly or in various combinations without limitation.
Accordingly, numerous variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, modification, addition or omission of at least one component, extraction of at least one component, and combination with components of other embodiments shall be included.

1 solid oxide fuel cell system, 2 stack, 3 reformer, 4 combustor, 5 desulfurizer, 11 air blower, 12, 14, 17 heat exchanger, 13 fuel gas control valve, 15 condenser, 16 Anode offgas blower 21 Cathode 22 Anode 23 Electrolyte 31 Air 32 Pure water 33 Fuel gas 34 Water vapor supply path 35 Combustor path 36 Recycle path 37 Anode offgas path 41 Stack temperature sensor 42 Reformer temperature sensor 43 Combustor temperature sensor 44 Air blower controller 45 Fuel gas regulation valve controller 46 Anode offgas blower controller 47 Stack voltage sensor.

Claims (3)

a stack comprising an anode, an electrolyte and a cathode;
a reformer that reacts the fuel gas and water vapor to produce an anode gas containing hydrogen;
a combustor that generates combustion gas for heating the catalyst of the reformer;
a fuel gas regulating valve for regulating the flow rate of the fuel gas to supply the anode gas to the anode;
an air blower for adjusting the flow rate of air supplied to the cathode;
an anode off-gas path branched into a recycling path for supplying the anode off-gas discharged from the anode to the reformer and a combustor path for supplying the anode off-gas to the combustor;
an anode off-gas blower provided in the anode off-gas path for adjusting a distribution ratio between the anode off-gas flowing through the recycling path and the anode off-gas flowing through the combustor path;
a reformer temperature sensor that detects the temperature of the catalyst of the reformer;
A solid oxide fuel cell system comprising a stack temperature sensor that detects the temperature of the stack,
The air blower adjusts the flow rate of the air supplied to the cathode based on the temperature of the stack detected by the stack temperature sensor, and the anode offgas blower is detected by the reformer temperature sensor. The fuel gas adjustment valve adjusts the distribution ratio between the anode off-gas flowing through the recycling path and the anode off-gas flowing through the combustor path based on the temperature of the catalyst that has been determined, and the fuel gas adjustment valve is detected by the reformer temperature sensor. a solid oxide fuel cell system, wherein the flow rate of the fuel gas is adjusted based on the temperature of the catalyst. a stack comprising an anode, an electrolyte and a cathode;
a reformer that reacts the fuel gas and water vapor to produce an anode gas containing hydrogen;
a combustor that generates combustion gas for heating the catalyst of the reformer;
a fuel gas regulating valve for regulating the flow rate of the fuel gas to supply the anode gas to the anode;
an air blower for adjusting the flow rate of air supplied to the cathode;
an anode off-gas path branched into a recycling path for supplying the anode off-gas discharged from the anode to the reformer and a combustor path for supplying the anode off-gas to the combustor;
an anode off-gas blower provided in the anode off-gas path for adjusting a distribution ratio between the anode off-gas flowing through the recycling path and the anode off-gas flowing through the combustor path;
a combustor temperature sensor that detects the temperature of the combustion gas in the combustor;
A solid oxide fuel cell system comprising a stack temperature sensor that detects the temperature of the stack,
The air blower adjusts the flow rate of the air supplied to the cathode based on the temperature of the stack detected by the stack temperature sensor, and the anode offgas blower is detected by the combustor temperature sensor. The distribution ratio between the anode off-gas flowing through the recycling path and the anode off-gas flowing through the combustor path is adjusted based on the temperature of the combustion gas obtained, and the fuel gas adjustment valve is detected by the combustor temperature sensor. and adjusting the flow rate of the fuel gas based on the temperature of the combustion gas. further comprising a stack voltage sensor that detects the voltage of the stack;
3. The solid oxide fuel cell system according to claim 1, wherein the fuel gas adjustment valve adjusts the flow rate of the fuel gas based on the voltage of the stack detected by the stack voltage sensor. .

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