JP2011222478A - Solid oxide type fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell capable of relatively readily detecting time-dependent changes of any two of supply flow rates of fuel gas, water for reforming, and air.SOLUTION: A solid oxide type fuel cell 2 includes fuel gas supply means for supplying fuel gas, water supply means for supplying water for reforming, a reformer 6 for reforming the fuel gas with water vapor using the water for reforming, air supply means 30 for supplying air, a fuel battery cell stack 8 performing power generation by oxidation and reduction of the reformed fuel gas and the air (oxygen), and a combustion chamber 34 disposed on a fuel gas exhaust side of the fuel battery cell stack 8. Temperatures of two measurement positions in relation to the reformer 6, the fuel battery cell stack 8 and the combustion chamber 34 are detected. Based on the temperatures thus detected for the two measurement positions, time-dependent changes of any two of supply flow rates of the fuel gas, the water for reforming, and the air are detected.

Description

  The present invention relates to a solid oxide fuel cell including a fuel cell stack that generates power using fuel gas as fuel.

  Fuel gas supply means for supplying fuel gas through the fuel gas supply flow path, water supply means for supplying reforming water through the water supply flow path, and steam reforming the fuel gas using the reforming water Reformer, air supply means for supplying air through an air supply channel, fuel cell stack for generating power by oxidation and reduction of reformed fuel gas and air (oxygen in the air), fuel 2. Description of the Related Art A fuel cell including a combustion chamber disposed on a fuel gas discharge side of a battery cell stack is known.

  In this fuel cell, for example, a fuel gas blower is disposed in the fuel gas supply flow path, and the flow rate of the fuel gas supplied through the fuel gas supply flow path is controlled by the fuel gas blower. Further, for example, a water supply pump is disposed in the water supply channel, and the flow rate of the reforming water supplied through the water supply channel is controlled by the water supply pump. Further, for example, an air blower is disposed in the air supply flow path, and the flow rate of air supplied through the air supply flow path is controlled by the air blower.

  In such a fuel cell, the performance of the fuel gas blower, the water supply pump and the air blower changes over time, and particularly when operated for a long period of time, the supply flow rate of the fuel gas by the fuel gas blower and the supply of reforming water by the water supply pump The flow rate and the air supply flow rate by the air blower fluctuate, which may affect the power generation reaction of the fuel cell stack.

  For this reason, a fuel cell has been proposed in which the supply flow rate of reforming water is controlled in response to changes in the performance of the water supply pump over time (for example, see Patent Document 1). In this fuel cell, the reformer is provided with temperature detecting means, and the voltage of the water supply pump (in other words, the water supply pump is set so that the temperature detected by the temperature detecting means becomes a predetermined temperature determined by a predetermined load factor. By controlling the number of rotations of the water supply pump in this way, it is possible to supply the reforming water without using a water flow meter so as not to be affected by the temporal change of the water supply pump.

JP 2005-150044 A

  However, in this known fuel cell, it is possible to eliminate fluctuations in performance over time of the water supply pump for controlling the supply flow rate of reforming water, but the same problem is caused by controlling the supply flow rate of fuel gas. The fuel gas blower and the air blower for controlling the supply flow rate of the air as the oxidant also have no problem with the fuel gas blower and the air blower.

  For example, if the fuel gas supply flow rate decreases due to changes in performance of the fuel gas blower over time, the generated power of the fuel cell stack decreases, and if this power decrease increases, the fuel cell stack may be damaged, When the gas supply flow rate is increased, steam reforming in the reformer is not performed as required, and this also causes damage to the fuel cell stack.

  In addition, for example, if the air supply flow rate decreases due to changes in the air blower over time, the generated power of the fuel cell stack decreases, and if this power decrease increases, the fuel cell stack may be damaged, When the supply flow rate increases, the temperature of the fuel cell stack decreases and the power generation efficiency decreases.

  An object of the present invention is to provide a fuel cell that can relatively easily detect a change with time of any two of the supply flow rates of fuel gas, reforming water, and air.

  Another object of the present invention is to provide a fuel cell that can relatively easily detect a change with time in the supply flow rates of fuel gas, reforming water, and air.

According to a first aspect of the present invention, there is provided a solid oxide fuel cell comprising a fuel gas supply means for supplying fuel gas from a fuel gas supply source through a fuel gas supply channel, and water for reforming as a water supply channel. Water supply means for supplying through, a reformer for steam reforming the fuel gas from the fuel gas supply means using the reforming water from the water supply means, and air as an oxidant air A plurality of air supply means for supplying through the supply flow path; and a plurality of fuel cells that generate power by oxidation and reduction of the reformed fuel gas reformed by the reformer and the oxidizing material from the air supply means Fuel cell stack provided, combustion chamber disposed on the fuel gas discharge side of the fuel cell stack, battery housing for housing the reformer, the fuel cell stack, and the combustion chamber When A solid oxide fuel cell comprising,
The temperature of two temperature measurement parts related to any one or two of the reformer, the fuel cell stack and the combustion chamber is detected, and based on the detected temperature of the two temperature measurement parts Further, it is characterized in that a change with time of any two of the supply flow rates of the fuel gas, the reforming water and the air is detected.

In the solid oxide fuel cell according to claim 2 of the present invention, a fuel gas flow rate control means for controlling a fuel gas supply flow rate is disposed in the fuel gas supply channel, The supply flow path is provided with water flow rate control means for controlling the supply flow rate of reforming water, and the air supply flow path is provided with air flow rate control means for controlling the supply flow rate of air, Furthermore, a control means for controlling the fuel gas flow rate control means, the water flow rate control means and the air flow rate control means is provided,
Based on the detected temperatures of the two temperature measurement parts, a change in supply flow rate of any two of the supply flow rates of fuel gas, reforming water and air is detected over time, and the control means detects the two detected flow rates. Two of the fuel gas flow rate control means, the water flow rate control means, and the air flow rate control means are corrected and controlled based on the change in supply flow rate over time.

According to a third aspect of the present invention, there is provided a solid oxide fuel cell comprising a fuel gas supply means for supplying fuel gas from a fuel gas supply source through a fuel gas supply channel, and water for reforming. Water supply means for supplying through the flow path; a reformer for steam reforming the fuel gas from the fuel gas supply means using the reforming water from the water supply means; and air as an oxidant An air supply means for supplying gas through an air supply flow path, and a fuel cell for generating power by oxidation and reduction of the reformed fuel gas reformed by the reformer and an oxidizing material from the air supply means A plurality of fuel cell stacks, a combustion chamber disposed on the fuel gas discharge side of the fuel cell stack, a battery for housing the reformer, the fuel cell stack, and the combustion chamber Containment housing A solid oxide fuel cell comprising a grayed,
The temperature of three temperature measurement parts related to any one or two or more of the reformer, the fuel cell stack and the combustion chamber is detected, and based on the detected temperature of the three temperature measurement parts Thus, it is characterized in that a change with time in the supply flow rates of fuel gas, reforming water and air is detected.

Further, in the solid oxide fuel cell according to claim 4 of the present invention, a fuel gas flow rate control means for controlling a supply flow rate of the fuel gas is disposed in the fuel gas supply flow path, and the water The supply flow path is provided with water flow rate control means for controlling the supply flow rate of reforming water, and the air supply flow path is provided with air flow rate control means for controlling the supply flow rate of air, Furthermore, a control means for controlling the fuel gas flow rate control means, the water flow rate control means and the air flow rate control means is provided,
Based on the detected temperatures of the three temperature measurement parts, a change with time of the supply flow rates of the fuel gas, the reforming water and the air is detected, and the control means detects the change with time of the detected three supply flow rates. The fuel gas flow rate control means, the water flow rate control means, and the air flow rate control means are corrected based on the control.

  Further, in the solid oxide fuel cell according to claim 5 of the present invention, the temperature at the temperature measurement site related to the reformer is the temperature in the reformer, and the fuel cell stack includes The temperature of the relevant temperature measurement site is the temperature in the vicinity of the fuel cell stack, and the temperature of the temperature measurement site related to the combustion chamber is the temperature of the combustion chamber or the exhaust from the combustion chamber. It is the temperature inside the heat exchanger for exhaust heat recovery for recovering exhaust heat of exhaust gas.

  In the solid oxide fuel cell according to claim 6 of the present invention, a normal operation mode in which an output current taken out from the fuel cell stack is changed, and an output current taken out from the fuel cell stack is maintained at a predetermined current. It is possible to operate by switching to the correction operation mode to be performed, and in the operation in the correction operation mode, a change with time in the supply flow rate is detected.

According to a seventh aspect of the present invention, there is provided a solid oxide fuel cell comprising a fuel gas supply means for supplying fuel gas from a fuel gas supply source through a fuel gas supply channel, and water for reforming. Water supply means for supplying through the flow path; a reformer for steam reforming the fuel gas from the fuel gas supply means using the reforming water from the water supply means; and air as an oxidant An air supply means for supplying gas through an air supply flow path, and a fuel cell for generating power by oxidation and reduction of the reformed fuel gas reformed by the reformer and an oxidizing material from the air supply means A plurality of fuel cell stacks, a combustion chamber disposed on the fuel gas discharge side of the fuel cell stack, a battery for housing the reformer, the fuel cell stack, and the combustion chamber Containment housing A solid oxide fuel cell comprising a grayed,
Detecting a temperature of a temperature measurement portion related to at least one of the reformer, the fuel cell stack, and the combustion chamber, and detecting an output voltage of a voltage measurement portion related to the fuel cell stack. A change with time of at least any two of the supply amounts of the fuel gas, the reforming water, and the air is detected based on the detection temperature of the temperature measurement part and the detection voltage of the voltage measurement part.

  Moreover, in the solid oxide fuel cell according to claim 8 of the present invention, two temperature measurement sites related to any one or two of the reformer, the fuel cell stack and the combustion chamber. And detecting the output voltage of the voltage measurement part related to the fuel cell stack, and based on the detection temperature of the two temperature measurement parts and the detection voltage of the voltage measurement part, a fuel gas, It is characterized by detecting changes with time in the supply flow rates of the reforming water and air.

According to a ninth aspect of the present invention, there is provided a solid oxide fuel cell comprising a fuel gas supply means for supplying fuel gas from a fuel gas supply source through a fuel gas supply channel, and water for reforming. Water supply means for supplying through the flow path; a reformer for steam reforming the fuel gas from the fuel gas supply means using the reforming water from the water supply means; and air as an oxidant An air supply means for supplying gas through an air supply flow path, and a fuel cell for generating power by oxidation and reduction of the reformed fuel gas reformed by the reformer and an oxidizing material from the air supply means A plurality of fuel cell stacks, a combustion chamber disposed on the fuel gas discharge side of the fuel cell stack, a battery for housing the reformer, the fuel cell stack, and the combustion chamber Containment housing A solid oxide fuel cell comprising a grayed,
Detecting output voltages of at least two voltage measurement parts related to the fuel cell stack, and based on the detected voltages of the at least two voltage measurement parts, at least the supply amounts of fuel gas, reforming water and air Any two of the changes over time are detected.

  In the solid oxide fuel cell according to claim 10 of the present invention, the output voltage of two voltage measurement sites related to the fuel cell stack is detected, and the reformer and the fuel cell are detected. Detecting a temperature of a temperature measurement part related to one of the stack and the combustion chamber, and based on the detection voltage of the two voltage measurement parts and the detection temperature of the temperature measurement part, fuel gas, water for reforming And a change with time in the supply flow rate of air is detected.

  Furthermore, in the solid oxide fuel cell according to claim 11 of the present invention, the output voltages of the three voltage measurement parts related to the fuel cell stack are detected, and the detected voltages of the three voltage measurement parts are detected. Based on the above, it is characterized in that a change with time in the supply flow rates of fuel gas, reforming water and air is detected.

  According to the solid oxide fuel cell of the first aspect of the present invention, the temperature of two temperature measurement sites related to any one or two of the reformer, the fuel cell stack and the combustion chamber is set. Based on the detected temperatures at these two temperature measurement sites, a change with time in any two of the supply flow rates of the fuel gas, the reforming water and the air is detected. Variations in the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate affect the steam reforming reaction in the reformer, the fuel cell reaction in the fuel cell stack, and the combustion in the combustion chamber. As a result, the temperature of the parts related to the reformer, the fuel cell stack and the combustion chamber changes. Therefore, by utilizing such a relationship, the temperatures of the two temperature measurement sites related to the reformer, the fuel cell stack, and the combustion chamber are detected, and the fuel gas and the reforming water are detected using these detected temperatures. The change in supply flow rate with time (or change in supply flow rate of reforming water and air with time, change in supply flow rate of fuel gas and air with time) can be detected.

  According to the solid oxide fuel cell of the second aspect of the present invention, the fuel gas and the reforming water (or the reforming water and air, based on the detected temperatures at the two temperature measurement sites described above, The control means detects the change with time of the supply flow rate of the fuel gas and reforming water (or the reforming water and air, the fuel gas and air), and detects the change with time of the supply flow rate of the fuel gas and air). Since the fuel gas flow control means and the water flow control means (or the water flow control means and the air flow control means, the fuel gas flow control means and the air flow control means) are corrected based on the control, the fuel gas flow control means and the water flow control are controlled. Means (or water flow control means and air flow control means, fuel gas flow control means and air flow control means), the fuel gas supply flow and the reforming water supply flow (or the reforming water supply flow Variations in the air supply flow rate, the fuel gas supply flow rate and the air supply flow rate) are corrected, and thus the fuel gas and the reforming water (or the reforming water and air, the fuel, and the fuel are not affected by the change in the performance over time. Gas and air).

  According to the solid oxide fuel cell of the third aspect of the present invention, three temperature measurement sites related to any one or more of the reformer, the fuel cell stack and the combustion chamber. Then, based on the detected temperatures at these three temperature measurement sites, changes over time in the supply flow rates of the fuel gas, the reforming water and the air are detected. When the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate fluctuate, the temperatures of the portions related to the reformer, the fuel cell stack, and the combustion chamber change as described above. Therefore, using such a relationship, the temperatures of the three temperature measurement sites related to the reformer, the fuel cell stack, and the combustion chamber are detected, and the fuel gas and the reforming water are detected using these detected temperatures. In addition, it is possible to detect a change over time in the air supply flow rate.

  According to the solid oxide fuel cell of the fourth aspect of the present invention, the supply flow rates of the fuel gas, the reforming water, and the air are changed over time based on the detected temperatures at the three temperature measurement sites described above. Since the change is detected, the control unit corrects and controls the fuel gas flow rate control unit, the water flow rate control unit, and the air flow rate control unit based on the detected amount of change in the supply flow rate of the fuel gas, reforming water, and air over time. , Fluctuations in the fuel gas supply flow rate, the reforming water supply flow rate and the air supply flow rate associated with changes in performance over time of the fuel gas flow rate control means, the water flow rate control means and the air flow rate control means are corrected. Fuel gas, reforming water, and air can be supplied without being affected by changes.

  In the solid oxide fuel cell according to claim 5 of the present invention, the temperature at the temperature measurement site related to the reformer is the temperature in the reformer and is related to the fuel cell stack. The temperature of the temperature measurement part to be measured is the temperature in the vicinity of the fuel cell stack, and the temperature of the temperature measurement part related to the combustion chamber is the temperature of the combustion chamber or exhaust heat of exhaust gas exhausted from the combustion chamber. Therefore, by using any two of these temperature measurement parts, fuel gas and reforming water (or reforming water and air, fuel gas) are used. And any change in the supply flow rate of fuel gas, reforming water, and air can be detected by using any three of these measurement parts. be able to.

  According to the solid oxide fuel cell of the sixth aspect of the present invention, in the operation of the correction operation mode in which the output current taken out from the fuel cell stack is maintained at a predetermined current, the above-described supply flow rate over time Since the change is detected, the above-described change with time of the supply flow rate can be accurately detected.

  According to the solid oxide fuel cell of claim 7 of the present invention, while detecting the temperature of the temperature measurement site related to any one of the reformer, the fuel cell stack and the combustion chamber, The output voltage of the voltage measurement part related to the fuel cell stack is detected, and based on the detection temperature of the temperature measurement part and the detection voltage of the voltage measurement part, any one of the supply flow rates of fuel gas, reforming water and air Detect changes in the two supply flow rates over time. Variations in the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate affect the steam reforming reaction in the reformer, the fuel cell reaction in the fuel cell stack, and the combustion in the combustion chamber. As a result, the temperature of the portion related to the reformer, the fuel cell stack, and the combustion chamber changes, and the output voltage of the portion related to the fuel cell stack changes. Therefore, using such a relationship, the temperature of the temperature measurement part related to the reformer, the fuel cell stack and the combustion chamber is detected, and the output voltage of the voltage measurement part related to the fuel cell stack is detected. By using these detected temperatures and detected voltages, changes in the supply flow rate of fuel gas and reforming water over time (or changes in the supply flow rate of reforming water and air over time, changes in the supply flow rates of fuel gas and air over time) Change) can be detected.

  In the solid oxide fuel cell according to claim 8 of the present invention, two temperature measurement sites related to any one or two of the reformer, the fuel cell stack and the combustion chamber are provided. In addition to detecting the temperature, the output voltage of the voltage measurement part related to the fuel cell stack is detected. Based on the detected temperature of the two temperature measurement parts and the detection voltage of the voltage measurement part, the fuel gas, the reforming water In addition, a change with time in the air supply flow rate is detected. When the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate fluctuate, the temperature of the parts related to the reformer, the fuel cell stack and the combustion chamber changes as described above, and the fuel cell The output voltage of the part related to the cell stack changes. Therefore, using such a relationship, the temperature of the two temperature measurement parts related to the reformer, the fuel cell stack and the combustion chamber and the output voltage of the voltage measurement part related to the fuel cell stack are detected. By using these detected temperatures and detected voltages, it is possible to detect changes over time in the supply flow rates of fuel gas, reforming water and air.

  In the solid oxide fuel cell according to claim 9 of the present invention, the output voltages of at least two voltage measurement parts related to the fuel cell stack are detected, and the detected voltages of these voltage measurement parts are detected. Based on this, a change with time in any two of the supply flow rates of the fuel gas, the reforming water and the air is detected. Variations in the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate affect the steam reforming reaction in the reformer, the fuel cell reaction in the fuel cell stack, and the combustion in the combustion chamber. As a result, the output voltage of the portion related to the fuel cell stack changes. Therefore, using such a relationship, output voltages of at least two voltage measurement sites related to the fuel cell stack are detected, and the detected flow voltage is used to determine the supply flow rates of the fuel gas and reforming water over time. Changes (or changes over time in the supply flow rates of reforming water and air, changes over time in the supply flow rates of fuel gas and air) can be detected.

  According to the solid oxide fuel cell of the present invention, the output voltage of the two voltage measurement portions related to the fuel cell stack is detected, and the reformer, the fuel cell stack And the temperature of the temperature measurement part related to any one of the combustion chambers, and based on the detection voltage of these two voltage measurement parts and the detection temperature of the temperature measurement part, the fuel gas, the reforming water and the air Detect changes in supply flow over time. When the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate fluctuate, the temperature of the parts related to the reformer, the fuel cell stack and the combustion chamber changes as described above, and the fuel cell The output voltage of the part related to the cell stack changes. Therefore, using such a relationship, the output voltage of two voltage measurement parts related to the fuel cell stack and the temperature measurement part related to any one of the reformer, the fuel cell stack and the combustion chamber. , And the change with time of the supply flow rates of the fuel gas, the reforming water and the air can be detected using these detection voltages and detection temperatures.

  Furthermore, according to the solid oxide fuel cell according to claim 11 of the present invention, the output voltages of the three voltage measuring portions related to the fuel cell stack are detected, and the detection of the three voltage measuring portions is detected. Based on the voltage, a change with time in the supply flow rates of the fuel gas, the reforming water and the air is detected. When the fuel gas supply flow rate, the reforming water supply flow rate, and the air supply flow rate fluctuate, the output voltage of the portion related to the fuel cell stack changes as described above, and the relationship between the fluctuations in the output voltage is utilized. Then, the output voltage of the three voltage measurement parts related to the fuel cell stack is detected, and the change with time of the supply flow rate of fuel gas, reforming water and air is detected using the detection voltage of these three parts. can do.

1 is a schematic diagram showing a first embodiment of a solid oxide fuel cell according to the present invention. FIG. The block diagram which shows the control system of the solid oxide fuel cell of FIG. The flowchart which shows a part of control by the control system of FIG. Schematic which shows 2nd Embodiment of the solid oxide fuel cell according to this invention. The block diagram which shows the control system of the solid oxide fuel cell of FIG. The flowchart which shows a part of control by the control system of FIG. Schematic which shows 3rd Embodiment of the solid oxide fuel cell according to this invention. Block diagram showing the control system of the solid oxide fuel cell of FIG. The simplified diagram which shows the fuel cell stack in 4th Embodiment of the solid oxide fuel cell according to this invention, and the structure relevant to this. The simplified diagram which shows the fuel cell stack in 5th Embodiment of the solid oxide fuel cell according to this invention, and the structure relevant to this.

  Hereinafter, embodiments of a solid oxide fuel cell according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
First, a first embodiment of a solid oxide fuel cell will be described with reference to FIGS. FIG. 1 is a schematic diagram showing the solid oxide fuel cell of the first embodiment, FIG. 2 is a block diagram showing a control system of the solid oxide fuel cell of FIG. 1, and FIG. It is a flowchart which shows a part of control by the control system of FIG.

  In FIG. 1, a solid oxide fuel cell 2 shown in the figure consumes fuel gas (for example, city gas, LP gas, etc.) to generate electric power, and vaporizes reforming water to generate water vapor. The vaporizer 4, the reformer 6 for reforming the fuel gas using steam, the reformed fuel gas reformed by the reformer 6 and the oxidation and reduction of air as the oxidant A solid oxide fuel cell stack 8 for performing

  The fuel cell stack 8 is configured by laminating a plurality of solid oxide fuel cells for generating power by a fuel cell reaction via a current collecting member. A zirconia doped with, for example, yttria is used as the solid electrolyte, which includes a conducting solid electrolyte, a fuel electrode provided on one side of the solid electrolyte, and an air electrode provided on the other side of the solid electrolyte.

  The fuel cell introduction side of the fuel cell stack 8 is connected to the reformer 6 via the reformed fuel gas supply channel 10, and the reformer 6 is connected via the gas / steam supply channel 12. Connected to the vaporizer 4. The vaporizer 4 is connected to a fuel gas supply source 16 (for example, an embedded pipe or a storage tank) for supplying fuel gas via the fuel gas supply flow path 14, and a gas flow rate is supplied to the fuel gas supply flow path 14. A total 18 and a fuel pump 20 are provided. The fuel pump 20 supplies the fuel gas from the fuel gas supply source 16 to the carburetor 4, and the gas flow meter 18 measures the supply flow rate of the fuel gas flowing through the fuel gas supply channel 14. Instead of connecting the fuel gas supply channel 14 to the vaporizer 4, it may be connected directly to the reformer 6.

  In this embodiment, the fuel pump 20 has a configuration in which the rotational speed varies in proportion to the voltage. When the supplied voltage increases (or decreases), the rotational speed increases (or decreases), and the fuel gas The supply flow rate of the fuel gas supplied through the supply flow path 14 increases (or decreases). Therefore, the fuel pump 20 also functions as a fuel gas flow rate control means for controlling the supply flow rate of the fuel gas supplied through the fuel gas supply flow path 14, and the fuel gas supply source 16, the fuel pump 20, and the fuel gas supply flow are controlled. The passage 14 constitutes fuel gas supply means for supplying fuel gas.

  The vaporizer 4 is connected to a water supply source 24 (for example, a water tank) via a water supply flow path 22, and a water pump 26 is disposed in the water supply flow path 22. The water pump 26 supplies the reforming water from the water supply source 24 to the vaporizer 4.

  In this embodiment, similarly to the fuel pump 20, the water pump 26 also has a configuration in which the rotation speed varies in proportion to the voltage. When the supplied voltage increases (or decreases), the rotation speed increases. (Or decreases), and the supply flow rate of the reforming water supplied through the water supply channel 22 increases (or decreases). Accordingly, the water pump 26 also functions as a water flow rate control means for controlling the supply flow rate of the reforming water supplied through the water supply flow path 14, and the water supply source 24, the water pump 26, and the water supply flow path 22 are And water supply means for supplying the reforming water.

  With this configuration, the fuel gas from the fuel gas supply source 16 is supplied to the vaporizer 4 through the fuel gas supply flow path 14, and the gas / steam supply flow path 12 is changed from the vaporizer 4. It is sent to the quality device 6. Further, the reforming water from the water supply source 24 is supplied to the vaporizer 4 through the water supply flow path 22, and is vaporized in the vaporizer 4 to become water vapor. This water vapor passes through the gas / water vapor supply flow path 12. It is fed to the reformer 6. In the reformer 6, the fuel gas is steam reformed with steam, and the reformed fuel gas subjected to steam reforming is fed to the fuel electrode side of the fuel cell stack 8 through the reformed fuel gas feed channel 10. .

  The air electrode introduction side of the fuel cell stack 8 is open to the atmosphere via an air supply passage 28, and an air blower 30 and an air flow meter 32 are disposed in the air supply passage 28. . The air blower 30 supplies air as an oxidizing material to the air electrode side of the fuel cell stack 8, and the air flow meter 32 measures the supply flow rate of air flowing through the air supply flow path 28.

  In this embodiment, the air blower 30 also has a configuration in which the rotation speed varies in proportion to the voltage, like the fuel pump 20 and the water pump 26, and when the supplied voltage increases (or decreases), The rotational speed increases (or decreases), and the supply flow rate of air supplied through the air supply flow path 28 increases (or decreases). Therefore, the air blower 30 also functions as an air flow rate control means for controlling the supply flow rate of air supplied through the air supply flow path 28, and the air blower 30 and the air supply flow path 28 are used for supplying air. Air supply means is configured.

  A combustion chamber 34 is provided on the fuel electrode stack 8 on the discharge side of the fuel electrode and the air electrode, and the reaction fuel gas (including surplus fuel gas) discharged from one end of the fuel cell stack 8 and the air electrode Air (containing oxygen) discharged from the side is supplied to the combustion chamber 34 and burned. An exhaust gas discharge passage 36 is connected to the combustion chamber 34, the discharge side thereof is opened to the atmosphere, and the exhaust gas from the combustion chamber 34 is discharged to the atmosphere through the exhaust gas discharge passage 36.

  In this embodiment, the vaporizer 4, the reformer 6, the fuel cell stack 8, and the combustion chamber 34 are accommodated in the battery accommodating housing 38. The illustrated battery housing 38 includes a housing body 40 made of metal (for example, stainless steel), and a heat insulating member (not shown) is disposed so as to cover the inner surface of the battery housing main body 40. A high temperature chamber 42 is defined inside the carburetor 4, the vaporizer 4, the reformer 6, and the fuel cell stack 8 are kept in a high temperature state in the high temperature chamber 42, and the vaporizer 4 is utilized by utilizing the heat in the high temperature chamber 42. The reforming water is vaporized and the reformer 6 performs steam reforming of the fuel gas.

  In this embodiment, the exhaust heat of the fuel cell 2 is collected as hot water. That is, a hot water storage tank 52 is provided in association with the fuel cell 2, and a heat exchanger 54 for exhaust heat recovery is disposed in the exhaust gas exhaust passage 36. The hot water storage tank 52 is provided with a circulation channel 56 extending through the heat exchanger 54 for exhaust heat recovery. One end of the hot water storage tank 52 is connected to the bottom of the hot water storage tank 52 and the other end is connected to the upper end of the hot water storage tank 52. A feed pump 58 is disposed in the circulation channel 56.

  With this configuration, when the feed pump 58 is activated during the power generation of the cell stack 8, the water in the hot water storage tank 52 is circulated through the circulation channel 56 and is exhausted by the heat exchanger 54 for exhaust heat recovery. Heat exchange is performed between the exhaust gas flowing through the gas discharge passage 36 and the water flowing through the circulation passage 56, and the hot water heated by this heat exchange is stored in the hot water storage tank 52.

  The fuel cell 2 is configured such that the supply flow rates of the fuel gas and the air are corrected and controlled in response to changes in performance of the fuel pump 20 and the air blower 30 over time. In general, in the fuel cell 2, the supply flow rate of the fuel gas supplied through the fuel gas supply channel 14 is closely related to the temperature of the reformer 6 and the temperature in the vicinity of the fuel cell stack 8. The supply flow rate of the air supplied through the air supply flow path 28 is closely related to the temperature of the reformer 6 and the temperature in the vicinity of the fuel cell stack 8. This close relationship varies depending on the type of fuel cell, generated power, and the like, but when the fuel cell 2 is actually operated and measured, the relationship shown in Table 1 is obtained experimentally as an example.

表１は、燃料電池２の設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路２８を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍の温度及び改質器６内の温度を示すもので、例えば空気の供給流量が３％上昇すると、燃料電池セルスタック８の近傍温度は所定温度（例えば、６５０℃）より３．００℃下がり、改質器６内の温度は所定温度（例えば、６００℃）より０．６０℃下がる。また、この表１は、上述した電流制限の稼働運転状態において、燃料ガス供給流路１４を流れる燃料ガスの供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍温度及び改質器６内の温度を示すもので、例えば燃料ガスの供給流量が３％上昇すると、燃料電池セルスタック８の近傍温度は所定温度（例えば、６５０℃）より１２．０℃上がり、改質器６内の温度は所定温度（例えば、６００℃）より２７．０℃上がる。この表１における「Ｒ２値」とは相関係数を示している。

Table 1 shows the air flowing through the air supply passage 28 in the current-limited operation state in which the fuel cell 2 is operated at the maximum load and the output current is maintained at a predetermined current (for example, 6 A) in the initial operation state of the fuel cell 2. This shows the temperature in the vicinity of the fuel cell stack 8 and the temperature in the reformer 6 that fluctuate every time the supply flow rate fluctuates by 1% (in this case, increase). For example, when the air supply flow rate rises by 3% The temperature in the vicinity of the fuel cell stack 8 is lowered by 3.00 ° C. from a predetermined temperature (for example, 650 ° C.), and the temperature in the reformer 6 is decreased by 0.60 ° C. from the predetermined temperature (for example, 600 ° C.). Further, this Table 1 shows that the fuel cell stack 8 changes every time the supply flow rate of the fuel gas flowing through the fuel gas supply passage 14 fluctuates by 1% (in this case, increases) in the above-described current-limited operation state. , And the temperature in the reformer 6, for example, when the fuel gas supply flow rate is increased by 3%, the temperature near the fuel cell stack 8 is 12.0 ° C. from a predetermined temperature (for example, 650 ° C.). The temperature inside the reformer 6 rises by 27.0 ° C. from a predetermined temperature (eg, 600 ° C.). “R2 value” in Table 1 indicates a correlation coefficient.

T1 (° C.) is the temperature in the reformer 6 in the operation state where the predetermined output current at the maximum load operation at the initial stage of installation is maintained at the predetermined current, and T 2 (° C.) is the temperature in the vicinity of the fuel cell stack 8. Assuming that the temperature in the reformer 6 is (t1) ° C. and the temperature in the vicinity of the fuel cell stack 8 is (t2) ° C. in the same current operation state (operation operation at a predetermined output current at the maximum load). The amount of temperature change based on the initial temperature is
Temperature change amount ΔT1 (° C.) in the reformer 6 = T1-t1 (1)
Temperature change ΔT2 (° C.) = T2−t2 (2) in the vicinity of the fuel cell stack 8
It becomes. When using the relationship of Table 1 and using the formulas (1) and (2), the deviation amount of the air supply flow rate (%) (deviation amount based on the supply flow rate in the above-mentioned operation state at the initial stage of installation) And the deviation amount (%) of the supply flow rate of fuel gas (deviation amount based on the supply flow rate in the above-mentioned operation state at the initial stage of installation)
Air divergence amount X (%) = − 1.098ΔT1 + 0.488ΔT2 (3)
Fuel gas deviation amount Y (%) = 0.0244ΔT1 + 0.122ΔT2 (4)
Thus, by using the temperature change amount ΔT1 in the reformer 6 and the temperature change amount ΔT2 in the vicinity of the fuel cell stack 8, the air supply flow rate deviation amount X (%) based on the above-described operating operation state in the initial stage of installation. ) And the deviation amount Y (%) of the fuel gas supply flow rate can be obtained by calculation.

  In order to correct the supply flow rates of the fuel gas and air using the above-described relationship, the following configuration is further provided. In order to detect the temperature of the reformer 6, first temperature detection means 62 is disposed in the reformer 6. Further, in order to detect the temperature in the vicinity of the fuel cell stack 8, the second temperature detection means 64 is disposed in the vicinity of the fuel cell stack 8 in the high temperature chamber 42.

  Correction of the fuel gas supply flow rate and the air supply flow rate using the detected temperatures of the first and second temperature detection means 62 and 64 is performed by the control system shown in FIG. Referring to FIG. 2 together with FIG. 1, the fuel cell 2 further includes control means 66 for controlling the fuel pump 20, the water pump 26, the air blower 30, and the like, and the first and second temperature detection means 62, 64. Detection signals from the air flow meter 32 and the fuel flow meter 18 are also sent to the control means 66.

  The control unit 66 includes an operation switching unit 68, a temperature change amount calculation unit 70, an air deviation amount calculation unit 72, and a fuel deviation amount calculation unit 74. The operation switching means 68 switches the operation state of the fuel cell between the normal operation mode and the correction operation mode. The operation in the normal operation mode is an operation mode in which the output power of the fuel cell stack 8 is changed in accordance with the power load and output, and the power generation output from the fuel cell stack 8 is controlled to be a predetermined power. (If the voltage fluctuates, the current fluctuates accordingly, for example, the current rises when the voltage drops), and is operated in this normal operation mode when operating in a normal power generation state. Further, the operation in the correction operation mode is an operation mode in which the fuel cell stack 8 is maintained at a predetermined load with a maximum load, and in this correction operation mode, the output current is maintained constant. The supply flow rate of the fuel gas is also maintained at a constant flow rate that is the output current, and when the air supply flow rate and the fuel gas supply flow rate are corrected, the operation is performed in this correction operation mode.

  Further, the temperature change amount calculation means 70 is a temperature T1 (° C.) in the reformer 6 in an operation state at a predetermined output current at the maximum load at the initial stage of installation, and a temperature T2 (° C.) in the vicinity of the fuel cell stack 8. ) Is used to calculate the temperature change amount ΔT1 in the reformer 6 and the temperature change amount ΔT2 in the vicinity of the fuel cell stack 8 using the above formulas (1) and (2).

  The air divergence amount calculating means 72 calculates the air divergence amount X (%) using the above equation (3) based on the temperature change amounts ΔT1 and ΔT2 calculated by the temperature change amount calculating means 70, and the fuel divergence amount. The amount calculation means 74 calculates the fuel divergence amount Y (%) using the above equation (4) based on the temperature change amounts ΔT1 and ΔT2.

  The control means 66 further includes an air correction amount calculation means 76, a fuel correction amount calculation means 78, an operation control means 80, and a memory means 82. The air correction amount calculation means 76 calculates the correction amount (increase or decrease) of the air supplied through the air supply flow path 28 based on the calculated air deviation amount X (%), and the fuel correction amount calculation means. 78 calculates the correction amount (increase or decrease) of the fuel gas supplied through the fuel gas supply flow path 14 based on the calculated fuel deviation amount Y (%). The operation control means 80 controls the rotational speed of the air blower 30 so that the flow rate of the air supplied to the air electrode side of the fuel cell stack 8 is corrected by the calculated correction amount, and the fuel cell stack The number of revolutions of the fuel pump 20 is controlled so that the flow rate of the fuel gas supplied to the fuel electrode 8 is corrected by the calculated correction amount.

  In the memory means 82, air divergence amount calculation data (information related to the above equation (3)) and fuel divergence amount calculation data (information related to the above equation (4)) are registered, and an air blower control map (drive voltage and The map information regarding the rotation speed) and the fuel pump control map (map information regarding the driving voltage and the rotation speed) are registered, and the inside of the reformer 6 in the operation operation state at the predetermined output current at the maximum load at the initial stage of installation. And the temperature T2 in the vicinity of the fuel cell stack 8 are stored.

  The correction control of the air supply flow rate and the fuel gas supply flow rate in the fuel cell 2 is performed according to the flowchart shown in FIG. Referring mainly to FIG. 2 and FIG. 3, when the air supply flow rate and the fuel gas supply flow rate are corrected, the operation switching means 68 switches to the operation in the correction operation mode (the mode in which the maximum load output current is constant). The operation in such a correction operation mode is performed at each start-up, for example, and is operated in the corrected state after the start-up.

  In the operation state of this correction operation mode, first, the first temperature detection means 62 detects the internal temperature of the reformer 6, and the second temperature detection means 64 detects the temperature in the vicinity of the fuel cell stack 8 ( In step S 1), detection signals from the first and second temperature detection means 62 and 64 are sent to the control means 66.

  When the temperature is detected in this way, the temperature change amount calculating means 70 is based on the detected temperature t1 of the first temperature detecting means 62 and the internal temperature T1 of the reformer 6 at the initial stage of setting stored in the memory means 82. Then, the temperature change amount ΔT1 of the reformer 6 is calculated using the above equation (1) (step S2), the detected temperature t2 of the second temperature detecting means 64 and the initial fuel set in the memory means 82 are stored. Based on the temperature T2 near the battery cell stack 8, the temperature ΔT2 near the fuel cell stack 8 is calculated using the above equation (2) (step S3).

  The air divergence amount calculating means 72 calculates the air divergence amount X using the above equation (3) based on the temperature change amounts ΔT1 and ΔT2 of the two temperature measurement points calculated by the temperature change amount calculating means 70. Then, the fuel divergence amount calculation means 74 calculates the fuel divergence amount Y using the above equation (4) based on the temperature change amounts ΔT1 and ΔT2 of these two temperature measurement locations (step S5). ). In this way, it is possible to detect a change in the supply flow rate of air and fuel gas over time using the detected temperatures at two locations related to the reformer 6 and the fuel cell stack 8.

  Thereafter, the supply flow rate is corrected using the air deviation amount X and the fuel deviation amount Y. That is, the air correction amount calculating means 76 calculates the air correction amount based on the air deviation amount X (step S7), and the fuel correction amount calculating means 78 calculates the fuel correction amount based on the fuel deviation amount Y. (Step S7). Thus, the operation control means 82 uses the air blower control map registered in the memory means 82 based on the air divergence amount X, and the rotation speed of the air blower 30 (specifically, the predetermined output current at the maximum load). (The number of revolutions in the operation state) is calculated (step S8), and the number of revolutions of the air blower 30 corresponding to the power generation output of the fuel cell 2 is set based on this number of revolutions. Further, the operation control means 82 uses the fuel pump control map registered in the memory means 82 based on the fuel divergence amount Y, so that the rotational speed of the fuel pump 20 (specifically, at a predetermined output current at the maximum load). The number of revolutions in the operating state is calculated (step S9), and the revolution of the fuel pump 20 corresponding to the power generation output of the fuel cell 2 is set based on this revolution number.

  Then, the control means 66 controls the operation of the air blower 30 based on the rotational speed set based on the air deviation amount X (step S10), and the fuel pump based on the rotational speed set based on the fuel deviation amount Y. 20 is controlled (step S11), and the supply flow rates of air and fuel gas are corrected in this way.

  After this correction is completed, the operation switching means 66 switches the operation mode from the correction operation mode to the normal operation mode (step S12), and the fuel cell 2 is operated in the normal operation mode, and the air blower 30 and the fuel pump 20 are operated. Is controlled with the rotational speed set to be corrected, and by controlling the operation in this way, air and fuel gas are supplied to the fuel cell stack 8 without being affected by fluctuations in the supply flow rate due to changes over time. Can do.

  In this embodiment, the operation state of the predetermined output current of the maximum load is set as the correction operation mode, but the power generation state of the predetermined load (for example, the load state of the rated power generation output) is not limited to such an operation state. Thus, the operation may be performed in an operation state in which the generated output current is maintained at a predetermined output current.

  Further, in this embodiment, the rotation speeds of the air blower 30 and the fuel pump 20 (in other words, the air supply flow rate and the fuel gas supply flow rate by the air supply unit and the fuel gas supply unit) are corrected. The rotation speeds of the air blower 30 and the water pump 26 (the air supply flow rate and the water supply flow rate by the air supply unit and the water supply unit) may be corrected, or the rotation of the fuel pump 20 and the water pump 26 may be corrected. The number (fuel gas supply flow rate and water supply flow rate by the fuel gas supply unit and the water supply unit) may be corrected.

  This will be further explained. Generally, there is a close relationship between the supply flow rate of reforming water supplied through the water supply flow path 22, the temperature of the reformer 6, and the temperature in the vicinity of the fuel cell stack 8 ( For this close relationship, see also the following description.) Therefore, such close relationship of the reforming water, the supply flow rate of the air supplied through the air supply flow path 28, and the temperature of the reformer 6 are as follows. And by using the close relationship with the temperature in the vicinity of the fuel cell stack 8, the internal temperature (T 1, t 1) of the reformer 6 and the temperature in the vicinity of the fuel cell stack 8 ( The water deviation amount Z and the air deviation amount X can be detected based on T2, t2), and the water pump 26 and the air can be detected in the same manner as described above based on the water deviation amount Z and the air deviation amount X. Blower 30 times (The water supply flow rate and the air supply flow rate by the water supply means and the air supply means) can be corrected and set, and in this way, the reforming water and the Air can be supplied as required.

  In addition, the above-described close relationship between the reforming water and the close relationship between the supply flow rate of the fuel gas supplied through the fuel gas supply flow path 14, the temperature of the reformer 6, and the temperature in the vicinity of the fuel cell stack 8. In the same manner as described above, the water deviation amount Z and the fuel deviation amount are based on the internal temperature (T1, t1) of the reformer 6 and the vicinity temperature (T2, t2) of the fuel cell stack 8 in the same manner as described above. Y can be detected, and based on the water deviation amount Z and the fuel deviation amount Y, the rotational speeds of the water pump 26 and the fuel pump 20 (by the water supply means and the fuel gas supply means) in the same manner as described above. Water supply flow rate and fuel gas supply flow rate) can be corrected, and in this way, water for reforming and fuel gas can be supplied as required without being subject to fluctuations in the supply flow rate due to changes over time. It is possible.

[Second Embodiment]
Next, a second embodiment of the solid oxide fuel cell will be described with reference to FIGS. 4 is a schematic view showing a solid oxide fuel cell according to the second embodiment, FIG. 5 is a block diagram showing a control system of the solid oxide fuel cell of FIG. 4, and FIG. It is a flowchart which shows a part of control by the control system of FIG. In the second embodiment, substantially the same members as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment, the supply flow rates of air, fuel gas, and reforming water are corrected and controlled in response to changes in performance of the air blower 30, fuel pump 20, and water pump 26 over time. Yes. More specifically, in general, in a fuel cell, the supply flow rate of air supplied through the air supply passage 28, the internal temperature of the reformer 6, the temperature in the vicinity of the fuel cell stack 8, and the temperature of the combustion chamber 34. Is closely related to the flow rate of the fuel gas supplied through the fuel gas supply flow path 14, the temperature of the reformer 6, the temperature in the vicinity of the fuel cell stack 8, and the temperature of the combustion chamber 34. Furthermore, there is a close relationship between the supply flow rate of reforming water supplied through the water supply flow path 22, the temperature of the reformer 6, the temperature in the vicinity of the fuel cell stack 8, and the temperature of the combustion chamber 34. As described above, this close relationship varies depending on the type of fuel cell, generated power, and the like. However, when the fuel cell is actually operated and measured, the relationship shown in Table 2 is obtained experimentally as an example.

表２は、燃料電池２Ａの設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路２８を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍温度、改質器６の内部温度及び燃焼室３４の温度を示すものである。また、この表２は、上述した電流制限の稼働運転状態において、水供給流路２２を流れる改質用水の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍温度、改質器６の内部温度及び燃焼室３４の温度、更には燃料ガス供給流路１４を流れる燃料ガスの供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍温度、改質器６の内部温度及び燃焼室３４の温度を示している。

Table 2 shows the air flowing through the air supply channel 28 in the current-limited operation state in which the output current is maintained at a predetermined current (for example, 6A) by operating at the maximum load in the operation state at the initial installation of the fuel cell 2A. 4 shows the temperature near the fuel cell stack 8, the internal temperature of the reformer 6, and the temperature of the combustion chamber 34 that fluctuate every time the supply flow rate fluctuates by 1% (in this case, increases). In addition, Table 2 shows that the fuel cell stack 8 that fluctuates every time the reforming water supply flow rate flowing through the water supply passage 22 fluctuates 1% (in this case, increases) in the above-described current-limiting operation state. , The temperature inside the reformer 6, the temperature of the combustion chamber 34, and the fuel gas supply flow rate through the fuel gas supply flow path 14 fluctuates every 1% (in this case, increases). The vicinity temperature of the cell stack 8, the internal temperature of the reformer 6, and the temperature of the combustion chamber 34 are shown.

The temperature in the reformer 6 is T1 (° C.), the temperature in the vicinity of the fuel cell stack 8 is T 2 (° C.), and combustion is performed in the operation state in which the predetermined output current at the maximum load operation at the initial installation is maintained at the predetermined current. The temperature of the chamber 34 is T3 (° C.), the internal temperature of the reformer 6 in the same operation state at the present time is t1 (° C.), the temperature in the vicinity of the fuel cell stack 8 is t2 (° C.), and the combustion chamber 34 Is the temperature change amount ΔT1 in the reformer 6 and the temperature change amount ΔT2 in the vicinity of the fuel cell stack 8 are expressed by the above formula ( 1) and (2), and the temperature change amount ΔT3 of the combustion chamber 34 is
Temperature change amount ΔT3 (° C.) of combustion chamber 34 = T3-t3 (5)
It becomes. Using the relationship of Table 2 and using equations (1), (2), and (5), the deviation amount X (%) of the supply flow rate of air, the deviation amount Y (%) of the supply flow rate of fuel gas, and Deviation amount Z (%) of the supply flow rate of reforming water is
Air divergence amount X (%) = − 2.109ΔT1 + 0.2284ΔT2 + 0.5319ΔT3 (6)
Fuel gas deviation amount Y (%) = 0.3594ΔT1 + 0.0361ΔT2 + 0.1761ΔT3 (7)
Water divergence amount Z (%) for reforming = 0.4688ΔT1−0.1202ΔT2 + 0.2464ΔT3 (8)
By using the temperature change amount ΔT1 in the reformer 6, the temperature change amount ΔT2 in the vicinity of the fuel cell stack 8, and the temperature change amount ΔT3 in the combustion chamber 34, the above-described operation operation state at the initial stage of installation is used as a reference. It is possible to calculate and obtain the deviation amount X (%) of the air supply flow rate, the deviation amount Y (%) of the fuel gas supply flow rate, and the deviation amount Z (%) of the reforming water supply flow rate.

  In order to correct the supply flow rates of fuel gas, air, and reforming water using the close relationship described above, the second embodiment is configured as follows. Similar to the first embodiment described above, the first temperature detecting means 62 is disposed in the reformer 6, the second temperature detecting means 64 is disposed in the vicinity of the fuel cell stack 8, and in addition, In order to detect the temperature of the combustion chamber 34, third temperature detection means 92 is provided in the combustion chamber 34. A water flow meter 94 is provided in the water supply channel 22.

  Correction of the fuel gas supply flow rate, the air supply flow rate, and the reforming water supply flow rate using the detected temperatures of the first to third temperature detection means 62, 64, 92 is performed by the control system shown in FIG. Referring to FIG. 5, control means 66A includes operation switching means 68, temperature change amount calculating means 70, air deviation amount calculating means 72, fuel deviation amount calculating means 74, air correction amount calculating means 76, fuel correction amount calculating means. 78, in addition to the operation control means 80 and the memory means 82A, a water deviation amount calculating means 96 and a water correction amount calculating means 98 are included.

  In the second embodiment, the temperature change amount calculation means 70 includes the temperature change amount ΔT3 in the combustion chamber 34 in addition to the temperature change amount ΔT1 in the reformer 6 and the temperature change amount ΔT2 in the vicinity of the fuel cell stack 8. Is calculated using the above equation (5). The air divergence amount calculating means 72 calculates the air divergence amount X (%) using the above equation (6) based on the temperature change amounts ΔT1, ΔT2 and ΔT3 calculated by the temperature change amount calculating means 70, and the fuel The deviation amount calculation means 74 calculates the fuel deviation amount Y (%) using the above equation (7) based on the temperature change amounts ΔT1, ΔT2, and ΔT3, and the water deviation amount calculation means 96 calculates the temperature change amount. Based on the amounts ΔT1, ΔT2, and ΔT3, the water deviation amount Z (%) is calculated using the above equation (8). Further, the water correction amount calculation means 98 calculates the correction amount (increase amount or decrease amount) of the reforming water supplied through the water supply passage 22 based on the calculated water deviation amount Z, and the operation control means 80 The rotation speed of the air blower 30 and the fuel pump 20 is corrected and controlled, and the rotation speed of the water pump 26 is controlled so that the flow rate of the reforming water supplied to the vaporizer 4 is corrected by the calculated correction amount. Further, the memory means 82A includes air divergence amount calculation data (information related to the above equation (6)), fuel divergence amount calculation data (information related to the above equation (7)), and water divergence amount calculation data (related to the above equation (8)). In addition to the air blower control map and fuel pump control map, a water pump control map (map information related to drive voltage and rotation speed) is registered, and moreover, a predetermined output at the maximum load at the initial stage of installation The temperature T1 in the reformer 6 in the operation operation state with current, the temperature T2 in the vicinity of the fuel cell stack 8, the temperature T3 in the combustion chamber 34, and the like are stored. Other configurations in the second embodiment are substantially the same as those in the first embodiment described above.

  The correction control of the air supply flow rate, the fuel gas supply flow rate, and the water supply flow rate in the fuel cell 2A is performed according to the flowchart shown in FIG. Referring mainly to FIGS. 5 and 6, when the air supply flow rate, the fuel gas supply flow rate, and the water supply flow rate are corrected, the operation switching means 68 switches to the operation of the correction operation mode, and the operation control of the correction operation mode is performed. Is performed in substantially the same manner as described above.

  First, the first temperature detecting means 62 detects the internal temperature of the reformer 6, the second temperature detecting means 64 detects the vicinity of the fuel cell stack 8, and the third temperature detecting means 92 is the combustion chamber 34. (Step S21), detection signals from the first to third temperature detection means 62, 64, and 92 are sent to the control means 66A.

  When the temperature is detected in this manner, the temperature change amount calculation means 70 calculates the temperature change amount ΔT1 of the reformer 6 in the same manner as described above (step S22), and also near the fuel cell stack 8 The temperature change amount ΔT2 is calculated (step S23), and further, based on the detected temperature t3 of the third temperature detecting means 92 and the vicinity temperature T3 of the fuel cell stack 8 at the initial stage of setting stored in the memory means 82A, the above formula ( 5) is used to calculate the temperature change amount ΔT3 of the combustion chamber 34 (step S24).

  Then, the air divergence amount calculation means 72 uses the above equation (6) based on the temperature change amounts ΔT1, ΔT2, and ΔT3 of the three temperature measurement points calculated by the temperature change amount calculation means 70, and uses the above equation (6). (Step S25), the fuel divergence amount calculating means 74 calculates the fuel divergence amount Y using the above equation (7) based on the temperature change amounts ΔT1, ΔT2, and ΔT3 of these three temperature measurement locations. (Step S26), the water divergence amount calculating means 96 calculates the water divergence amount Z using the above equation (8) based on the temperature change amounts ΔT1, ΔT2, and ΔT3 of these three temperature measurement locations (Step S27). ). In this way, it is possible to detect changes over time in the air, fuel gas, and reforming water using the detected temperatures at the three locations related to the reformer 6, the fuel cell stack 8, and the combustion chamber 34. it can.

  Thereafter, the supply flow rate is corrected using the air deviation amount X, the fuel deviation amount Y, and the water deviation amount Z. That is, the air correction amount calculation means 76 calculates the air correction amount based on the air deviation amount X (step S28), and the fuel correction amount calculation means 78 calculates the fuel correction amount based on the fuel deviation amount Y. (Step S29) The water correction amount calculation means 98 calculates a water correction amount based on the water deviation amount Z (Step S30). Thus, the operation control means 82 calculates the rotational speed of the air blower 30 in the same manner as described above (step S31), and based on this rotational speed, the rotational speed of the air blower 30 corresponding to the power generation output of the fuel cell 2A. And the rotational speed of the fuel pump 20 is calculated (step S32), and based on this rotational speed, the rotational speed of the fuel pump 20 corresponding to the power generation output of the fuel cell 2A is set. Further, the operation control means 82 uses the water pump control map registered in the memory means 82A based on the water deviation amount Z, and the rotation speed of the water pump 26 (specifically, at a predetermined output current at the maximum load). The number of revolutions in the operating state is calculated (step S33), and the rotation of the water pump 26 corresponding to the power generation output of the fuel cell 2A is set based on this number of revolutions.

  Then, the control means 66A controls the operation of the air blower 30 based on the rotational speed set based on the water deviation amount X (step S34), and the fuel pump 20 based on the rotational speed set based on the fuel deviation amount Y. Is controlled (step S35), and the water pump 26 is controlled based on the rotational speed set based on the water deviation amount Z (step S36). In this way, supply of air, fuel gas, and reforming water is performed. The flow rate is corrected.

  After this correction is completed, the operation switching means 66 switches the operation mode from the correction operation mode to the normal operation mode (step S37), and the fuel cell 2A operates in the normal operation mode, as in the above-described embodiment. The air blower 30, the fuel pump 20 and the water pump 26 are controlled to operate with the corrected rotational speed conditions. By operating in this way, the air, Fuel gas and reforming water can be supplied as required.

  Also in the second embodiment, the power generation output current may be maintained in a predetermined output current in a power generation state of a predetermined load (for example, a load state of a rated power generation output).

  For example, in the above-described embodiment, the reformer 6 (inside thereof), the fuel cell stack 8 as the temperature measurement part closely related to the fluctuation of the air flow rate, the fuel gas flow rate, and the water supply flow rate. However, instead of one of these temperature measurement parts, an exhaust heat recovery heat exchanger 54 (inside) associated with the combustion chamber 34 may be selected. In the above-described embodiment, the reformer 6, the fuel cell stack 8, and the combustion chamber 34 are each provided as one location for measuring the temperature related to the reformer 6, the fuel cell stack 8, and the combustion chamber 34. However, there may be two locations for any one of the reformer 6, the fuel cell stack 8 and the combustion chamber 34, and depending on the case, any one of the reformer 6, the fuel cell stack 8 and the combustion chamber 34 may be used. There can be three places for one.

  In the above-described embodiment, the temperature of the temperature measurement portion related to the reformer 6, the fuel cell stack 8, and the combustion chamber 34 is used. Alternatively, instead of using all of them, the output voltage of the voltage measurement portion related to the fuel cell stack 8 may be used.

[Third Embodiment]
Next, with reference to FIG.7 and FIG.8, the solid oxide fuel cell of 3rd Embodiment is demonstrated. FIG. 7 is a schematic view showing a solid oxide fuel cell according to the third embodiment, and FIG. 8 is a block diagram showing a control system of the solid oxide fuel cell of FIG. In the following embodiments, members substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  7 and 8, the third embodiment is configured such that the supply flow rates of air and fuel gas are corrected and controlled in response to changes in the performance of the air blower 30 and the fuel pump 20 over time. . Further, to explain, in the fuel cell, as described above, the supply flow rate of the air supplied through the air supply passage 28, the internal temperature of the reformer 6, the temperature in the vicinity of the fuel cell stack 8, and the combustion chamber 34 In addition to the temperature, there is a close relationship with the output voltage of the fuel cell stack 8, the supply flow rate of the fuel gas supplied through the fuel gas supply channel 14, the temperature of the reformer 6, In addition to the vicinity temperature and the temperature of the combustion chamber 34, there is also a close relationship with the output voltage of the fuel cell stack 8, and the supply flow rate of reforming water supplied through the water supply passage 22 and the temperature of the reformer 6, In addition to the temperature near the fuel cell stack 8 and the temperature of the combustion chamber 34, there is a close relationship with the output voltage of the fuel cell stack 8. As described above, this close relationship varies depending on the type of fuel cell, generated power, and the like. However, when the fuel cell is actually operated and measured, the relationship shown in Table 3 is obtained experimentally as an example.

  In the third embodiment, the temperature in the vicinity of the fuel cell stack 8 and the output voltage of the fuel cell stack 8 among these relationships are used.

表３は、燃料電池２Ｂの設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路２８を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍温度及び燃料電池セルスタック８の出力電圧を示すものである。また、この表３は、上述した電流制限の稼働運転状態において、水供給流路２２を流れる改質用水の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の近傍温度及び燃料電池セルスタック８の出力電圧を示している。

Table 3 shows the air flowing through the air supply passage 28 in the current-limited operation state in which the output current is maintained at a predetermined current (for example, 6A) by operating at the maximum load in the operation state at the initial installation of the fuel cell 2B. This shows the temperature near the fuel cell stack 8 and the output voltage of the fuel cell stack 8 that fluctuate every time the supply flow rate fluctuates by 1% (in this case, increases). Further, this Table 3 shows that the fuel cell stack 8 that fluctuates every time the reforming water supply flow rate flowing through the water supply passage 22 fluctuates 1% (in this case, increases) in the above-described current-limiting operation state. And the output voltage of the fuel cell stack 8 are shown.

The temperature in the vicinity of the fuel cell stack 8 in the operation state in which the predetermined output current during the maximum load operation at the initial stage of installation is maintained at the predetermined current is T2 (° C.), and the output voltage of the fuel cell stack 8 is V (V). When the temperature near the fuel cell stack 8 in the same operation state at the present time is t2 (° C.) and the output voltage of the fuel cell stack 8 is v (V), the fuel is based on the initial temperature. The temperature change amount ΔT2 in the vicinity of the battery cell stack 8 is the above equation (2), and the output voltage change amount ΔV of the fuel cell stack 8 is
Output voltage change amount ΔV (V) = V−v (9) of the fuel cell stack 8
It becomes. Using the relationship of Table 3 and using equations (2) and (9), the deviation amount X (%) of the air supply flow rate and the deviation amount Z (%) of the water supply flow rate are:
Air deviation amount X (%) = ΔV−3.00ΔT2 (10)
Water deviation amount Z (%) = − 2.50ΔV + 2.50ΔT2 (11)
Thus, by using the temperature change amount ΔT2 in the vicinity of the fuel cell stack 8 and the output voltage change amount ΔV of the fuel cell stack 8, the air supply flow rate deviation amount X ( %) And the deviation amount Z (%) of the supply flow rate of the reforming water can be obtained by calculation.

  In order to correct the supply flow rates of air and reforming water using the close relationship described above, the third embodiment is configured as follows. A temperature detection unit 64 is disposed in the vicinity of the fuel cell stack 8, and a voltage detection unit 102 for detecting the output voltage of the fuel cell stack 8 is further provided. This voltage detection means 102 is disposed in the power generation output line 104 of the fuel cell stack 8 and detects the output voltage from the fuel cell stack 8. A water flow meter 94 is provided in the water supply channel 22.

  Correction of the air supply flow rate and the reforming water supply flow rate using the detection temperature of the temperature detection means 64 and the detection voltage of the voltage detection means 102 is performed by the control system shown in FIG. Referring to FIG. 8, the control means 66B includes an operation switching means 68, a temperature change amount calculation means 70, an air deviation amount calculation means 72, an air correction amount calculation means 76, an operation control means 80, and a memory means 82B. Voltage change amount calculation means 106, water deviation amount calculation means 96, and water correction amount calculation means 98 are included.

  The voltage change amount calculation means 106 in the third embodiment calculates the change amount ΔV of the output voltage of the fuel cell stack 8 using the above equation (9). Further, the air divergence amount calculating means 72 uses the above equation (10) based on the temperature change amount ΔT2 calculated by the temperature change amount calculating means 70 and the output voltage change amount ΔV calculated by the voltage change amount calculating means 106. The water divergence amount X (%) is calculated, and the water divergence amount calculation means 96 calculates the water divergence amount Z (%) using the above equation (11) based on the temperature change amount ΔT2 and the output voltage change amount ΔV. To do. Further, the water correction amount calculation means 98 calculates the correction amount (increase amount or decrease amount) of the reforming water supplied through the water supply passage 22 based on the calculated water deviation amount Z, and the operation control means 80 The rotational speeds of the air blower 30 and the water pump 26 are corrected and controlled. In this regard, the memory means 82B stores air divergence amount calculation data (information related to the above equation (10)) and water divergence amount calculation data (information related to the above equation (11)), as well as air. A blower control map, a water pump control map, and the like are registered, and the temperature T2 in the vicinity of the fuel cell stack 8 and the output voltage V of the fuel cell stack 8 in an operation state with a predetermined output current at the maximum load at the initial stage of installation. Is memorized. Other configurations in the third embodiment are substantially the same as those in the first embodiment described above.

  An outline of correction control of the air supply flow rate and the water supply flow rate in the fuel cell 2B is as follows. That is, detection signals from the temperature detection means 64 and the voltage detection means 102 are sent to the control means 66B, and the temperature change amount calculation means 70 calculates the temperature change amount ΔT2 near the fuel cell stack 8 in the same manner as described above. The voltage variation calculation means 106 calculates the voltage variation ΔV of the output voltage of the fuel cell stack 8.

  The air divergence amount calculating means 72 calculates the air divergence amount X using the above equation (10) based on the temperature change amount ΔT2 by the temperature change amount calculating means 70 and the voltage change amount ΔV by the voltage change amount calculating means 106. Further, the water divergence amount calculating means 96 calculates the water divergence amount Z using the above equation (11) based on the temperature change amount ΔT2 and the voltage change amount ΔV. In this way, the amount of change over time of the air and the reforming water can be detected using the detected temperature associated with the fuel cell stack 8 and the detected output voltage associated with the fuel cell stack 8.

  When the divergence amounts X and Z of the air and the reforming water are obtained in this way, the supply flow rate is corrected using these. That is, the air correction amount calculation unit 76 calculates an air correction amount based on the air deviation amount X, and the water correction amount calculation unit 98 calculates a water correction amount based on the water deviation amount Z. Then, as described above, the operation control means 82 calculates the rotational speed of the air blower 30, sets the rotational speed of the air blower 30 corresponding to the power generation output of the fuel cell 2B, and sets the rotational speed to the set rotational speed. Based on this, the air blower 30 is controlled to operate, the rotation speed of the water pump 26 is calculated, the rotation of the water pump 26 corresponding to the power generation output of the fuel cell 2A is set, and the water pump 26 is controlled based on the set rotation speed. The operation is controlled, and the supply flow rate of air and reforming water is corrected in this way, and even in this way, the same effect as that of the above-described embodiment can be achieved.

  In the third embodiment, the temperature in the vicinity of the fuel cell stack 8 is used as the temperature of the temperature measurement part. However, as is understood from the above description, the temperature is related to the reformer 6 or the fuel chamber 34. The same effect can be achieved even if the temperature at the temperature measurement site is used.

  In the third embodiment, the air divergence amount and the water divergence amount are calculated to calculate the rotation speeds of the air blower 30 and the water pump 26 (in other words, the air supply flow rate and the water supply flow rate by the air supply unit and the water supply unit). In the same manner as described above, the air deviation amount and the fuel deviation amount are calculated using the voltage change amount ΔV of the fuel cell stack 8 to calculate the rotation speeds of the air blower 30 and the fuel pump 20 ( (Air supply flow rate and fuel gas supply flow rate by the air supply means and the fuel gas supply means) may be corrected, or the fuel deviation amount and the water deviation amount are calculated by using this voltage change amount ΔV. 20 and the rotation speed of the water pump 26 (fuel gas supply flow rate and water supply flow rate by the fuel gas supply means and the water supply means) may be corrected.

  In the third embodiment, the change amount ΔV of the output voltage at the voltage measurement site related to the fuel cell stack 8 and the change amount ΔT2 of the temperature near the fuel cell stack 8 (or the change amount of the temperature of the reformer 6). The air supply flow rate and the water supply flow rate by the air supply means and the water supply means (or the fuel gas supply flow rate and the water supply by the fuel gas supply means and the water supply means) using ΔT1 and the temperature change amount ΔT3 of the combustion chamber 34 may be used. The flow rate, the air supply means and the fuel gas supply means) are corrected and controlled. As will be understood from the above description, the voltage measurement portion related to the fuel cell stack 8 is controlled. Using the amount of change in output voltage and the amount of change in temperature at two temperature measurement sites related to the reformer 6, the fuel cell stack 8 and the combustion chamber 34, air supply means, fuel gas Supply means and air supply flow rate by the water supply means, the fuel gas supply flow rate and water supply flow rate may be such that the correction control.

  For example, when the temperature related to the fuel cell stack 8 and the combustion chamber 34 is used as the temperature and the voltage related to the fuel cell stack 8 is used as the output voltage, the operation is as follows. More specifically, when the fuel cell is actually operated and measured, the supply flow rate of air supplied through the air supply flow path 22, the output voltage of the fuel cell stack 8, the temperature near the fuel cell stack 8, and the combustion The relationship between the temperature of the chamber 34, the supply flow rate of the fuel gas supplied through the fuel gas supply channel 14, the output voltage of the fuel cell stack 8, the temperature near the fuel cell stack 8, and the temperature of the combustion chamber 34. In addition, the relationship between the supply flow rate of reforming water supplied through the water supply flow path 22, the output voltage of the fuel cell stack 8, the temperature in the vicinity of the fuel cell stack 8, and the temperature of the combustion chamber 34 is shown as an example. The results shown in 4 are obtained experimentally.

表４は、燃料電池の設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路２８を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の出力電圧、燃料電池セルスタック８の近傍温度及び燃焼室３４の温度を示すものである。また、この表４は、上述した電流制限の稼働運転状態において、燃料ガス供給流路１４を通して流れる燃料ガスの供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の出力電圧、燃料電池セルスタック８の近傍温度及び燃焼室３４の温度、更には水供給流路２２を流れる改質用水の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８の出力電圧、燃料電池セルスタック８の近傍温度及び燃焼室３４の温度を示している。

Table 4 shows the flow of air flowing through the air supply passage 28 in the current-limited operation state in which the output current is maintained at a predetermined current (for example, 6A) by operating at the maximum load in the operation state at the initial installation of the fuel cell. It shows the output voltage of the fuel cell stack 8, the temperature in the vicinity of the fuel cell stack 8, and the temperature of the combustion chamber 34 that change every time the supply flow rate changes by 1% (in this case, increases). Further, this Table 4 shows that the fuel cell stack 8 that changes every time the supply flow rate of the fuel gas flowing through the fuel gas supply passage 14 fluctuates 1% (in this case, increases) in the above-described current-limited operation state. The fuel fluctuates each time the supply flow rate of reforming water flowing through the water supply passage 22 fluctuates by 1% (in this case, increases). The output voltage of the battery cell stack 8, the vicinity temperature of the fuel battery cell stack 8, and the temperature of the combustion chamber 34 are shown.

The output voltage of the fuel cell stack 8 is V (V) and the temperature in the vicinity of the fuel cell stack 8 is T2 (° C.) in the operation state in which the predetermined output current at the maximum load operation at the initial installation is maintained at the predetermined current. The temperature of the combustion chamber 34 is T3 (° C.), the output voltage of the fuel cell stack 8 is v (V) in the same operation state at the present time, the temperature near the fuel cell stack 8 is t2 (° C.), and combustion Assuming that the temperature of the chamber 34 is t3 (° C.), with respect to the amount of change relative to the initial installation, the amount of change in output voltage ΔV of the fuel cell stack 8, the amount of temperature change ΔT2 near the fuel cell stack 8 and the combustion chamber 34 The temperature change amount ΔT3 is expressed by the above equations (9), (2), and (5). Using the relationship in Table 4 and using equations (9), (2), and (5), the deviation amount X (%) of the supply flow rate of air, the deviation amount Y (%) of the supply flow rate of fuel gas, and Deviation amount Z (%) of the supply flow rate of reforming water is
Air deviation amount X (%) = − 1.22ΔV−0.73ΔT2 + 0.88ΔT3
(12)
Fuel gas deviation amount Y (%) = − 0.71ΔV + 0.67ΔT2−0.71ΔT3
... (13)
Water deviation Z (%) for reforming = −0.08ΔV + 0.08ΔT2 + 0.03ΔT3
(14)
By using the change amount ΔV of the output voltage of the fuel cell stack 8, the temperature change amount ΔT 2 near the fuel cell stack 8, and the temperature change amount ΔT 3 of the combustion chamber 34, the above-described operating operation state at the initial stage of installation is used as a reference. It is possible to calculate and obtain the air supply flow rate deviation amount X (%), the fuel gas supply flow rate deviation amount Y (%), and the reforming water supply flow rate deviation amount Z (%).

  Therefore, the fuel gas, air, and reforming water supply flow rates are corrected as required based on these air supply flow rate deviation amount X, fuel gas supply flow rate deviation amount Y, and reforming water supply flow rate deviation amount Z. By doing so, fluctuations in the supply flow rate due to changes over time can be suppressed, and air, fuel gas, and reforming water can be supplied to the fuel cell stack 8 as required.

[Fourth Embodiment]
Next, a fourth embodiment of the solid oxide fuel cell according to the present invention will be described. In the fourth embodiment, the temperature is not detected at the temperature measurement part, but the detection voltages of the two voltage measurement parts related to the fuel cell stack 8 are used, and these two voltage measurement parts are used. For example, a configuration as shown in FIG. 9 can be used to detect the output voltage at.

  In FIG. 9, the fuel cell stack 8C includes a first cell stack unit 110 on the left side and a second cell stack unit 112 on the right side, and the total output of the first and second cell stack units 110 and 112 is a fuel cell. This is the output power of the stack 8C. In this embodiment, the first voltage detection unit 114 is provided in association with the first cell stack unit 110, the second voltage detection unit 116 is provided in association with the second cell stack unit 112, and the first voltage detection unit 114 is provided. Detects the output voltage of the first cell stack unit 110, and the second voltage detection means 116 detects the output voltage of the second cell stack unit 112.

  The fourth embodiment is a control system (not shown) substantially the same as that of the third embodiment, and the detection signals (detection voltages) from the first and second voltage detection means 114 and 116 are control means. To be sent to. The voltage change amount calculating means of the control means calculates the voltage change amount of the first and second cell stack units 110 and 112, and the air divergence amount calculating means is the voltage change amount calculating means of the first cell stack unit 110. An air divergence amount X (%) is calculated based on the change amount ΔV1 of the output voltage and the change amount ΔV2 of the output voltage of the second cell stack unit 112, and the water divergence amount calculation means is based on the voltage change amounts ΔV1 and ΔV2. Calculate water divergence amount Z (%). In this case, the temperature change amount calculating means is omitted.

  In the fuel cell, as described above, the supply flow rate of air supplied through the air supply flow channel, the supply flow rate of fuel gas supplied through the fuel gas supply flow channel, and the reforming water supplied through the water supply flow channel. There is a close relationship between the supply flow rate and the output voltage of the fuel cell stack 8 (in this case, the output voltages of the first and second cell stack units 110 and 112). As described above, this close relationship varies depending on the type of fuel cell, generated power, and the like. However, when the fuel cell is actually operated and measured, the relationship shown in Table 5 is obtained experimentally as an example.

表５は、燃料電池２Ｃの設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｃの第１及び第２セルスタックユニット１１０，１１２の出力電圧を示すとともに、水供給流路２２を流れる改質用水の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｃの第１及び第２セルスタックユニット１１０，１１２の出力電圧を示している。

Table 5 shows the flow of air flowing through the air supply channel in the current-limited operation state in which the output current is maintained at a predetermined current (for example, 6A) by operating at the maximum load in the operation state at the initial installation of the fuel cell 2C. Reformation that flows through the water supply flow path 22 as well as the output voltage of the first and second cell stack units 110 and 112 of the fuel cell stack 8C that changes every time the supply flow rate changes by 1% (in this case, increases). The output voltage of the 1st and 2nd cell stack unit 110,112 of the fuel cell stack 8C which changes whenever the supply flow rate of water is changed 1% (in this case, increases) is shown.

The output voltages of the first and second cell stack units 110 and 112 of the fuel cell stack 8C in the operation operation state in which the predetermined output current during the maximum load operation at the initial stage of installation is maintained at the predetermined current are V1 (V) and V2 (V ), And when the output voltages of the first and second cell stack units 110 and 112 of the fuel cell stack 8C in the same operation state at the present time are v1 (V) and v2 (V), the output voltage at the initial stage of installation The change amounts ΔV1 and ΔV2 of the output voltages of the first and second cell stack units 110 and 112 of the fuel cell stack 8C with reference to
Output voltage change amount ΔV1 (V) = V1−v1 of first cell stack unit 110
... (15)
Output voltage change amount ΔV2 (V) = V2−v2 of second cell stack unit 110
... (16)
It becomes. Using the relationship of Table 5 and using equations (15) and (16), the deviation amount X (%) of the air supply flow rate and the deviation amount Z (%) of the water supply flow rate are:
Air deviation amount X (%) = 2.97ΔV1 + 5.41ΔV2 (17)
Water deviation amount Z (%) = − 4.14ΔV1−4.50ΔV2 (18)
Thus, by using the output voltage changes ΔV1 and ΔV2 of the first and second cell stack units 110 and 112 in the fuel cell stack 8C, the deviation amount of the air supply flow rate based on the above-described operating operation state at the initial installation stage It is possible to calculate and obtain X (%) and the deviation amount Z (%) of the supply flow rate of the reforming water.

  Therefore, the air supply flow rate deviation amount X and the reforming water supply flow rate deviation amount Z are calculated in this way, and the air and reforming water supply flow rates are calculated based on the air deviation amount X and the water deviation amount Z. By correcting as required, fluctuations in the supply flow rate due to changes over time can be suppressed, and air and reforming water can be supplied to the fuel cell stack 8C as required.

  In the fourth embodiment, the air divergence amount and the water divergence amount are calculated to correct the air supply flow rate and the water supply flow rate by the air supply unit and the water supply unit. The air supply amount and the fuel supply amount by the air supply means and the fuel gas supply means are calculated by using the voltage change amounts ΔV1 and ΔV2 of the first and second cell stack units 110 and 112 in the stack 8C. The gas supply flow rate may be corrected, or the fuel divergence amount and the water divergence amount are calculated using these voltage change amounts ΔV1 and ΔV2, and the fuel gas supply flow rate and the water supplied by the fuel gas supply means and the water supply means are calculated. The supply flow rate may be corrected.

  In the fourth embodiment, the output voltage variations ΔV1 and ΔV2 of the two voltage measurement portions (that is, the first and second cell stack units 110 and 112) related to the fuel cell stack 8C are used for air. Air supply flow and water supply flow by supply means and water supply means (or fuel gas supply flow and water supply flow by fuel gas supply means and water supply means, air supply flow and fuel gas supply by air supply means and fuel gas supply means As can be understood from the above description, the amount of change in the output voltage at the two voltage measurement sites related to the fuel cell stack 8C, the reformer, and the fuel cell The air supply by the air supply means, the fuel gas supply means and the water supply means using the amount of change in the temperature of the temperature measurement portion related to either the stack or the combustion chamber. The supply flow rate, the fuel gas supply flow rate, and the water supply flow rate can be corrected and controlled.

  When the output voltage of the two voltage measuring parts related to the fuel cell stack 8C is used as the output voltage and the temperature of the temperature measuring part (for example, inside the reformer) related to the reformer is used as the temperature, It becomes like this. Furthermore, to explain, when the fuel cell is actually operated and measured, the flow rate of the air supplied through the air supply channel, the fuel supplied through the fuel supply channel, as can be easily understood from the above description. The gas supply flow rate and the reforming water supply flow rate supplied through the water supply flow path, and the output voltages of the two power measurement sites (in this case, the first and second cell stack units 110 and 112) in the fuel cell stack 8C. As an example of the relationship between the temperature inside the reformer and the temperature inside the reformer, those shown in Table 6 are obtained experimentally.

表６は、燃料電池の設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｃの第１及び第２セルスタックユニット１１０，１１２の出力電圧及び改質器の温度と、燃料ガス供給流路を通して流れる燃料ガスの供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｃの第１及び第２セルスタックユニット１１０，１１２の出力電圧及び改質器の温度と、水供給流路を流れる改質用水の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｃの第１及び第２セルスタックユニット１１０，１１２の出力電圧及び改質器の温度とを示している。

Table 6 shows the supply of air flowing through the air supply channel in the current-limited operation state in which the output current is maintained at a predetermined current (for example, 6A) by operating at the maximum load in the operation state at the initial installation of the fuel cell. Each time the flow rate changes by 1% (in this case, increases), the output voltage of the first and second cell stack units 110 and 112 of the fuel cell stack 8C, the temperature of the reformer, and the fuel gas supply flow path The output voltage of the first and second cell stack units 110 and 112 of the fuel cell stack 8C and the temperature of the reformer, which change every time the supply flow rate of the flowing fuel gas fluctuates by 1% (in this case, increases), water, The first and second cell stack units 110 and 112 of the fuel cell stack 8C that change every time the supply flow rate of reforming water flowing through the supply flow path fluctuates 1% (in this case, increases). It indicates the temperature of the output voltage and the reformer.

The output voltages of the first and second cell stack units 110 and 112 of the fuel cell stack 8C in the operation operation state in which the predetermined output current during the maximum load operation at the initial stage of installation is maintained at the predetermined current are V1 (V) and V2 (V ), And the temperature of the reformer is T1 (° C.), and the output voltages of the first and second cell stack units 110 and 112 of the fuel cell stack 8C in the same operation state at the present time are v1 (V), Assuming v2 (V) and the reformer temperature to be t1 (° C.), with respect to the amount of change relative to the initial stage of installation, the output voltage change amount ΔV1 of the first cell stack unit 110 of the fuel cell stack 8C, the fuel cell The output voltage variation Δ2 and the reformer temperature variation ΔT1 of the second cell stack unit 112 of the cell stack 8C are expressed by the above equations (15), (16), and (1). Using the relationships in Table 6 and using equations (15), (16), and (1), the deviation amount X (%) of the supply flow rate of air, the deviation amount Y (%) of the supply flow rate of fuel gas, and Deviation amount Z (%) of the supply flow rate of reforming water is
Air deviation amount X (%) = − 0.92ΔV1 + 1.19ΔV2 + 0.05ΔT1
... (19)
Fuel gas deviation amount Y (%) = − 0.37ΔV1−0.46ΔV2−0.20ΔT1
... (20)
Water deviation amount Z (%) for reforming = 0.62ΔV1 + 0.62ΔV2−0.18ΔT1
... (21)
By using the output voltage variations ΔV1 and ΔV2 of the first and second cell stack units 110 and 112 of the fuel cell stack 8C and the temperature variation ΔT1 in the reformer, the above-described operation operation at the initial stage of installation is performed. It is possible to calculate and obtain a deviation amount X (%) of the air supply flow rate based on the state, a deviation amount Y (%) of the fuel gas supply flow rate, and a deviation amount Z (%) of the reforming water supply flow rate. Become.

  Therefore, as described above, the supply flow rates of the fuel gas, air, and reforming water are required based on the deviation amount X of the air supply flow rate, the deviation amount Y of the fuel gas supply flow rate, and the deviation amount Z of the supply flow rate of reforming water. By correcting as described above, fluctuations in the supply flow rate due to changes over time can be suppressed, and air, fuel gas, and reforming water can be supplied to the fuel cell stack 8C as required.

  In the embodiment described above, the change amounts ΔV1, ΔV2 of the output voltage of the two voltage measurement portions (first and second cell stack units 110, 112) related to the fuel cell stack 8C and the temperature change of the reformer 6 are changed. The amount ΔT1 is used to correct and control the air supply flow rate, the fuel gas supply amount, and the water supply flow rate by the air supply means, the fuel gas supply means, and the water supply means. As can be easily understood from the above description, the fuel cell Using the amount of change in output voltage at two voltage measurement locations related to the cell stack 8 and the amount of change in temperature at the temperature measurement location related to the fuel cell stack 8 or the combustion chamber 34, air supply means and fuel gas supply The air supply flow rate, the fuel gas supply flow rate, and the water supply flow rate by the means and the water supply unit can be corrected and controlled.

[Fifth Embodiment]
Next, a fifth embodiment of the solid oxide fuel cell according to the present invention will be described. In the fifth embodiment, detection voltages at three voltage measurement sites related to the fuel cell stack are used. To detect output voltages at three voltage measurement sites, for example, as shown in FIG. Can be configured.

  In FIG. 10, the fuel cell stack 8D includes a first cell stack unit 122 on the left side, a second cell stack unit 124 in the middle, and a third cell stack unit 126 on the right side, and the first to third cell stack units 122, Reference numerals 124 and 126 constitute most of the fuel cell unit 8D. In this embodiment, the first voltage detection means 114 is provided in relation to the first cell stack unit 122, the second voltage detection means 116 is provided in relation to the second cell stack unit 124, and the third cell stack unit. 126, a third voltage detecting means 118 is provided, the first voltage detecting means 114 detects the output voltage of the first cell stack unit 122 as a first voltage measuring part, and the second voltage detecting means 116 The output voltage of the second cell stack unit 124 as the second voltage measurement part is detected, and the third voltage detection means 126 detects the output voltage of the third cell stack unit 126 as the third voltage measurement part.

  In the fuel cell, as described above, the supply flow rate of air supplied through the air supply flow channel, the supply flow rate of fuel gas supplied through the fuel gas supply flow channel, and the reforming water supplied through the water supply flow channel. There is a close relationship between the supply flow rate and the output voltages of the three voltage measurement portions related to the fuel cell stack 8 (in this case, the output voltages of the first to third cell stack units 122, 124, 126). . As described above, this close relationship varies depending on the type of fuel cell, generated power, and the like. However, when the fuel cell is actually operated and measured, the relationship shown in Table 7 is obtained experimentally as an example. .

表７は、燃料電池２Ｄの設置初期の運転状態において、最大負荷時で稼働させて出力電流を所定電流（例えば、６Ａ）に維持した電流制限の運転状態において、空気供給流路を流れる空気の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｄの第１〜第３セルスタックユニット１２２，１２４，１２６の出力電圧と、燃料ガス供給流路を流れる燃料ガスの供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｄの第１〜第３セルスタックユニット１２２，１２４，１２６の出力電圧と、水供給流路を流れる改質用水の供給流量が１％変動（この場合、増加）する毎に変動する燃料電池セルスタック８Ｄの第１〜第３セルスタックユニット１２２，１２４，１２６の出力電圧とを示している。

Table 7 shows the state of the air flowing through the air supply channel in the current-limited operating state in which the output current is maintained at a predetermined current (for example, 6A) by operating at the maximum load in the initial operating state of the fuel cell 2D. The output voltage of the first to third cell stack units 122, 124, and 126 of the fuel cell stack 8D that changes every time the supply flow rate changes by 1% (in this case, increases), and the fuel gas that flows through the fuel gas supply channel The output voltage of the first to third cell stack units 122, 124, and 126 of the fuel cell stack 8D that changes whenever the supply flow rate of the fuel cell changes by 1% (in this case, increases) and the reforming that flows through the water supply flow path The output voltage of the 1st-3rd cell stack unit 122,124,126 of the fuel cell stack 8D which fluctuates whenever the supply flow rate of water is changed 1% (in this case, increases) is shown. To have.

The output voltages of the first to third cell stack units 122, 124, and 126 of the fuel cell stack 8D in the operation state in which the predetermined output current at the maximum load operation at the initial installation is maintained at the predetermined current are V1 (V) and V2. (V), V3 (V), and the output voltages of the first to third cell stack units 122, 124, 126 of the fuel cell stack 8D in the same operation state at the present time are v1 (V), v2 (V ), V3 (V), the variations ΔV1 and ΔV2 of the output voltages of the first and second cell stack units 122 and 124 of the fuel cell stack 8D based on the output voltage at the initial installation are expressed by the above equation (15). ) And (16), and the output voltage change ΔV3 of the third cell stack unit 126 is
Output voltage change amount ΔV3 (V) = V3−v3 of third cell stack unit 126
(22)
It becomes. Using the relationship of Table 7 and using equations (15), (16), and (22), the deviation amount X (%) of the supply flow rate of air, the deviation amount Y (%) of the supply flow rate of fuel gas, and The deviation amount Z (%) of the water supply flow rate is
Air divergence amount X (%) = − 1.17ΔV1−0.13ΔV2 + 0.77ΔV3
(23)
Fuel gas deviation amount Z (%) = − 0.60ΔV1 + 4.69ΔV2−3.00ΔV3
... (24)
Water deviation amount Z (%) = 1.55ΔV1 + 5.32ΔV2-2.74ΔV3
... (25)
By using the output voltage changes ΔV1, ΔV2, and ΔV3 of the first to third cell stack units 122, 124, and 126 in the fuel cell stack 8D, the air supply is based on the above-described operation operation state at the initial installation stage. It is possible to calculate and obtain the flow rate deviation amount X (%), the fuel gas supply flow rate deviation amount Y (%), and the reforming water supply flow rate deviation amount Z (%).

  Accordingly, the air supply flow rate deviation amount X, the fuel gas supply flow rate deviation amount Y, and the reforming water supply flow rate deviation amount Z are calculated in this way, and the air deviation amount X, the fuel gas deviation amount Y, and the water deviation are calculated. By correcting the supply flow rate of air, fuel gas, and reforming water as required based on the amount Z, fluctuations in the supply flow rate due to changes over time are suppressed, and air, fuel gas, and reforming water are supplied to the fuel cell stack. 8D can be supplied as required.

  While various embodiments of the fuel cell according to the present invention have been described above, the present invention is not limited to these embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

  Further, for example, in the above-described embodiment, the exhaust heat of the fuel cell 2 (2A, 2B) is recovered as hot water (in other words, provided with the hot water storage tank 52). Can be similarly applied to a configuration in which the hot water is not recovered (in other words, the hot water storage tank 52 is omitted).

  Further, for example, in the above-described embodiment, the fuel gas supply flow rate is controlled by changing the number of revolutions of the fuel pump 20, but instead of such a configuration, the fuel gas flow rate in the fuel gas supply channel 14 is controlled. For example, a fuel gas flow rate control valve may be provided as the control means, and the flow rate may be controlled by the fuel gas flow rate control valve. Further, the supply flow rate of the reforming water is controlled by changing the rotation speed of the water pump 26. Instead of such a configuration, for example, a water flow control valve as a water flow control means is provided in the water supply flow path 22. The flow rate may be controlled by the water flow rate control valve. Further, the supply flow rate of air (oxidizing material) is controlled by changing the rotation speed of the air blower 30. Instead of such a configuration, for example, air flow control is provided in the air supply passage 28 as air flow control means. A valve may be provided, and the air flow control valve may be used to control the flow rate.

2, 2A, 2B, 2C, 2D Fuel cell 4 Vaporizer 6 Reformer 8, 8C, 8D Fuel cell stack 14 Fuel gas supply channel 20 Fuel pump 22 Water supply channel 26 Water pump 28 Air supply channel 30 Air blower 34 Combustion chamber 52 Hot water storage tank 54 Waste heat recovery heat exchanger 62, 64, 92 Temperature detection means 66, 66A, 66B Control means 72 Air deviation amount calculation means 74 Combustion deviation amount calculation means 96 Water deviation amount calculation means 102 , 114, 116, 118 Voltage detection means 110, 112, 122, 124, 126 Cell stack unit

Claims (11)

A fuel gas supply means for supplying fuel gas from a fuel gas supply source through the fuel gas supply flow path; a water supply means for supplying reforming water through the water supply flow path; and A reformer for steam reforming the fuel gas using reforming water from the water supply means; an air supply means for supplying air as an oxidant through an air supply channel; and the reformer A fuel cell stack comprising a plurality of fuel cells that generate power by oxidation and reduction of the reformed fuel gas and the oxidizing material from the air supply means, and the fuel gas of the fuel cell stack A solid oxide fuel cell comprising a combustion chamber disposed on the discharge side, and a battery housing for housing the reformer, the fuel cell stack and the combustion chamber,
The temperature of two temperature measurement parts related to any one or two of the reformer, the fuel cell stack and the combustion chamber is detected, and based on the detected temperature of the two temperature measurement parts A solid oxide fuel cell characterized by detecting a change in supply flow rate of any two of the supply flow rates of fuel gas, reforming water and air. The fuel gas supply channel is provided with fuel gas flow rate control means for controlling the supply flow rate of fuel gas, and the water supply channel is provided with a water flow rate for controlling the supply flow rate of reforming water. Control means is provided, and the air supply flow path is provided with air flow control means for controlling the supply flow rate of air, and further, the fuel gas flow control means, the water flow control means, and the air flow control. Control means for controlling the means are provided,
Based on the detected temperatures of the two temperature measurement parts, a change in supply flow rate of any two of the supply flow rates of fuel gas, reforming water and air is detected over time, and the control means detects the two detected flow rates. 2. The solid according to claim 1, wherein two corresponding ones of the fuel gas flow rate control unit, the water flow rate control unit, and the air flow rate control unit are subjected to correction control based on an amount of change in supply flow rate with time. Oxide fuel cell. A fuel gas supply means for supplying fuel gas from a fuel gas supply source through the fuel gas supply flow path; a water supply means for supplying reforming water through the water supply flow path; and A reformer for steam reforming the fuel gas using reforming water from the water supply means; an air supply means for supplying air as an oxidant through an air supply channel; and the reformer A fuel cell stack comprising a plurality of fuel cells that generate power by oxidation and reduction of the reformed fuel gas and the oxidizing material from the air supply means, and the fuel gas of the fuel cell stack A solid oxide fuel cell comprising a combustion chamber disposed on the discharge side, and a battery housing for housing the reformer, the fuel cell stack and the combustion chamber,
The temperature of three temperature measurement parts related to any one or two or more of the reformer, the fuel cell stack and the combustion chamber is detected, and based on the detected temperature of the three temperature measurement parts A solid oxide fuel cell characterized by detecting changes with time in the supply flow rates of fuel gas, reforming water and air. The fuel gas supply channel is provided with fuel gas flow rate control means for controlling the supply flow rate of fuel gas, and the water supply channel is provided with a water flow rate for controlling the supply flow rate of reforming water. Control means is provided, and the air supply flow path is provided with air flow control means for controlling the supply flow rate of air, and further, the fuel gas flow control means, the water flow control means, and the air flow control. Control means for controlling the means are provided,
Based on the detected temperatures of the three temperature measurement parts, a change with time of the supply flow rates of the fuel gas, the reforming water and the air is detected, and the control means detects the change with time of the detected three supply flow rates. The solid oxide fuel cell according to claim 3, wherein the fuel gas flow rate control means, the water flow rate control means, and the air flow rate control means are corrected based on the control.   The temperature at the temperature measurement site related to the reformer is the temperature inside the reformer, and the temperature at the temperature measurement site related to the fuel cell stack is the temperature in the vicinity of the fuel cell stack. And the temperature of the temperature measurement part related to the combustion chamber is the temperature of the combustion chamber or the exhaust heat recovery heat exchanger for recovering the exhaust heat of the exhaust gas exhausted from the combustion chamber. The solid oxide fuel cell according to any one of claims 1 to 4, wherein the temperature is a temperature.   The operation can be performed by switching between a normal operation mode in which the output current taken out from the fuel cell stack is changed and a correction operation mode in which the output current taken out from the fuel cell stack is maintained at a predetermined current. The solid oxide fuel cell according to any one of claims 1 to 4, wherein a change with time in the supply flow rate is detected. A fuel gas supply means for supplying fuel gas from a fuel gas supply source through the fuel gas supply flow path; a water supply means for supplying reforming water through the water supply flow path; and A reformer for steam reforming the fuel gas using reforming water from the water supply means; an air supply means for supplying air as an oxidant through an air supply channel; and the reformer A fuel cell stack comprising a plurality of fuel cells that generate power by oxidation and reduction of the reformed fuel gas and the oxidizing material from the air supply means, and the fuel gas of the fuel cell stack A solid oxide fuel cell comprising a combustion chamber disposed on the discharge side, and a battery housing for housing the reformer, the fuel cell stack and the combustion chamber,
Detecting a temperature of a temperature measurement portion related to at least one of the reformer, the fuel cell stack, and the combustion chamber, and detecting an output voltage of a voltage measurement portion related to the fuel cell stack. And detecting a change with time of at least any two of the supply amounts of fuel gas, reforming water, and air based on the detected temperature of the temperature measuring portion and the detected voltage of the voltage measuring portion. Physical fuel cell.   The temperature of two temperature measurement parts related to any one or two of the reformer, the fuel cell stack, and the combustion chamber is detected, and the voltage measurement part related to the fuel cell stack is detected. An output voltage is detected, and a change with time in the supply flow rates of the fuel gas, the reforming water and the air is detected based on the detection temperature of the two temperature measurement parts and the detection voltage of the voltage measurement part. The solid oxide fuel cell according to claim 7. A fuel gas supply means for supplying fuel gas from a fuel gas supply source through the fuel gas supply flow path; a water supply means for supplying reforming water through the water supply flow path; and A reformer for steam reforming the fuel gas using reforming water from the water supply means; an air supply means for supplying air as an oxidant through an air supply channel; and the reformer A fuel cell stack comprising a plurality of fuel cells that generate power by oxidation and reduction of the reformed fuel gas and the oxidizing material from the air supply means, and the fuel gas of the fuel cell stack A solid oxide fuel cell comprising a combustion chamber disposed on the discharge side, and a battery housing for housing the reformer, the fuel cell stack and the combustion chamber,
Detecting output voltages of at least two voltage measurement parts related to the fuel cell stack, and based on the detected voltages of the at least two voltage measurement parts, at least the supply amounts of fuel gas, reforming water and air A solid oxide fuel cell characterized in that any two changes over time are detected.   The output voltage of two voltage measurement parts related to the fuel cell stack is detected, and the temperature of the temperature measurement part related to any one of the reformer, the fuel cell stack and the combustion chamber is detected. And detecting changes over time in the supply flow rates of the fuel gas, the reforming water and the air based on the detection voltage of the two voltage measurement parts and the detection temperature of the temperature measurement part. 9. The solid oxide fuel cell according to 9. Detecting output voltages of three voltage measurement sites related to the fuel cell stack, and changing the supply flow rates of fuel gas, reforming water and air over time based on the detection voltages of the three voltage measurement sites The solid oxide fuel cell according to claim 9, wherein the solid oxide fuel cell is detected.

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