JP6879732B2 - Reduction processing system control device, reduction processing system, reduction processing system control method and reduction processing system control program - Google Patents

Description

The present invention relates to a control device for a reduction treatment system, a reduction treatment system, a control method for the reduction treatment system, and a control program for the reduction treatment system.

As one of the fuel cells, a solid oxide fuel cell (SOFC) is known. The SOFC has a fuel cell composed of a solid electrolyte, fuel electrodes formed on both sides thereof, and an air electrode. SOFC supplies fuel gas to the fuel electrode, supplies oxidant gas to the air electrode, and chemically reacts the fuel contained in the fuel gas and the oxygen contained in the oxidant gas via a solid electrolyte to generate electric power. Is generated.

SOFC fuel cell cells are formed through a firing process. The fuel cell is fired in an electric or gas furnace. The fuel electrode of SOFC is composed of a conductive material with a catalyst component added. For example, nickel (Ni) is used as the material as the catalyst component. Further, the SOFC substrate may contain a substance constituting a solid electrolyte and a substance constituting the fuel electrode so as to reduce the difference in thermal expansion coefficient from the fuel electrode, and when the material constituting the substrate also contains Ni. There is. When Ni is used as a constituent material of SOFC, for example, it is present as NiO in a fuel cell after adding Ni oxide powder, forming it into a predetermined shape, and then oxidizing and sintering it by firing. In the state of NiO, the fuel electrode of SOFC cannot generate enough power. In order to bring SOFC into a predetermined power generation state, it is necessary to reduce NiO to Ni.

For example, Patent Document 1 describes a material containing a nickel oxide and a cobalt oxide and having the mass of the cobalt metal component adjusted with respect to the total mass of the nickel metal component and the cobalt metal component in the solid oxide form. It is disclosed that it is used as a catalyst material for electrodes of a fuel cell. Further, the relationship between the reduction rate of the catalyst and the reduction operation time is disclosed. Further, conventionally, the reduced state of nickel has been detected by measuring the voltage between the electrodes, but it is disclosed that the actual reduced state of nickel could not be detected accurately.

JP-A-2015-49993

However, in the invention disclosed in Patent Document 1, since the reduction rate is increased by the material, there is a problem that it cannot be correctly detected whether or not the reduction of the cell stack actually used is completed. In addition, it was necessary to use X-ray absorption fine structure analysis to measure the reduction rate.
In addition, since the reduction process is managed by the reduction time, if the reduction state is confirmed after the reduction process, the reduction may be insufficient, and if the reduction is insufficient, the power generation performance of the cell stack cannot be fully exhibited. There was a problem that the quality deteriorated.
Furthermore, we were trying to determine the completion of the reduction treatment by changing the electrical resistance component due to the change in the properties of the fuel electrode, with the main purpose of reducing the NiO of the fuel electrode to Ni, but the effect of NiO remaining on the fuel electrode on the electrical resistance. Was small, and it was inadequate to judge the completion of the reduction process with high accuracy.

The present invention has been made in view of such circumstances, and a control device for a reduction treatment system, a reduction treatment system, a control method for the reduction treatment system, and a reduction treatment capable of determining the completion of the reduction treatment by a simple method. The purpose is to provide a control program for the system.

In order to solve the above problems, the control device of the reduction treatment system, the reduction treatment system, the control method of the reduction treatment system, and the control program of the reduction treatment system of the present invention employ the following means.
The control device of the reduction treatment system according to the first aspect of the present invention includes a reduction furnace that performs reduction treatment on the form of a cell stack containing at least one fuel cell used in a fuel cell, and at least one said cell stack. It is a control device of a reduction processing system equipped with a voltage sensor for measuring the cell stack voltage of the power extraction portion of the above, and controls the reduction furnace to perform the reduction processing at a temperature equal to or higher than a predetermined temperature exceeding 900 ° C. Then, when the cell stack voltage reaches a predetermined voltage, the resistance of the base tube of the cell stack is measured, and when the resistance reaches the predetermined resistance, the resistance of the base tube of the cell stack reaches the predetermined resistance. It is determined that the reduction process is completed, and control is performed to end the reduction process.

Conventionally, a method has been adopted in which the reduction treatment of the cell stack is performed at a temperature of about 900 ° C., and the reduction is completed by lengthening the time to allow a margin for judgment so as not to cause problems such as insufficient reduction. This time, by setting the temperature of the reduction treatment of the cell stack to a slightly higher temperature than before, many unexpected effects could be obtained. That is, according to this configuration, by performing the reduction treatment of the cell stack at a temperature higher than a predetermined temperature exceeding 900 ° C., which is a higher temperature than the conventional one, the reduction treatment of the cell stack is further reduced in a shorter time than before. You can proceed to the rate.
As a result, the reduction process of the cell stack is advanced to a higher reduction rate than before, so that the reduction shortage can be minimized and the quality of the cell stack can be improved.
Further, by performing the reduction treatment at a temperature higher than a predetermined temperature exceeding 900 ° C., which is a higher temperature than before, the reduction reaction of the metal oxide is promoted and the reduction is likely to proceed. Therefore, the reduction treatment should be terminated at an early stage. Can improve productivity.
Further, by performing the reduction treatment of the cell stack at a temperature higher than a predetermined temperature exceeding 900 ° C., which is a higher temperature than before, the cell internal resistance and the electrolyte resistance are lowered, so that even if the change in the resistance of the substrate tube is small. The current (leakage current) flowing through the substrate tube can be detected accurately by the cell stack voltage. Here, by reducing the metal oxide (for example, nickel oxide) contained in the cell stack, the resistance of the substrate tube increases and the leakage current decreases as the reduction of the substrate tube progresses. As a result, it is possible to determine whether or not the reduction process is completed based on the value of the cell stack voltage.
Further, since it is determined whether or not the reduction process is completed based on whether or not the cell stack voltage has reached a predetermined voltage, it is possible to easily determine the completion of the reduction process of the cell stack.
Here, the cell stack voltage represents the voltage of a fuel cell in which one or a plurality of fuel cell cells formed in the cell stack are connected.
Further, according to this configuration, the resistance of the base tube of the cell stack is measured, and when the predetermined resistance is reached, the reduction process is completed. Therefore, in addition to the voltage monitoring, the resistance of the base tube can also be used for judgment. The completion of the reduction process can be determined more accurately.

In the first aspect, the predetermined temperature of the reduction treatment of the reduction furnace may be equal to or higher than a temperature at which the slope of the temperature change of the electrolyte resistance is −0.1 Ω · cm / 10 ° C. or higher.

In the first aspect, the predetermined temperature of the reduction treatment of the reduction furnace may be 930 ° C. or higher.

In the first aspect, when the cell stack voltage reaches 95% or more of the theoretical electromotive force of the fuel cell, it may be determined that the reduction process is completed, and control may be performed to end the reduction process.

According to this configuration, the completion of the reduction process is determined by whether or not the cell stack voltage reaches 95% or more of the theoretical electromotive force of the fuel cell, so that the reduction state of the base tube can be correctly managed. It is possible, and the completion of the reduction process can be determined with high accuracy.

In the first aspect, the voltage sensor is installed in a predetermined cell stack among a plurality of the cell stacks, and when all the cell stack voltages measured by the voltage sensors reach a predetermined voltage, the voltage sensor is described. It may be determined that the reduction treatment is completed, and control is performed to end the reduction treatment.

According to this configuration, the voltage sensor is installed in a predetermined cell stack, and when all the cell stack voltages reach a predetermined voltage, it is determined that the reduction process is completed. Therefore, the reduction process in the reduction furnace varies. It is possible to more accurately determine the completion of the reduction process.

In the first aspect, the reduction process may be terminated when the resistance of the substrate tube of the cell stack reaches a predetermined resistance value of 10 MΩ to 100 MΩ.

According to this configuration, since the completion of the reduction treatment is judged by whether or not the resistance of the substrate tube reaches a predetermined resistance value of 10 MΩ to 100 MΩ, it is possible to correctly manage the reduction state of the substrate tube. Yes, it is possible to accurately judge the completion of the reduction process.

In the first aspect, the fuel cell may be a solid oxide fuel cell.

The reduction treatment system according to the second aspect of the present invention performs reduction treatment on the form of a cell stack in which a control device according to any one of the above and a plurality of fuel cell cells used for a fuel cell are connected in series. It is provided with a reduction furnace for performing the reduction and a voltage sensor for measuring the cell stack voltage of the power extraction portion of the cell stack.

The control method of the reduction treatment system according to the third aspect of the present invention is the case where the reduction treatment is performed on the form of the cell stack including at least one fuel cell used in the fuel cell, and the reduction treatment of at least one of the cell stacks A control method for a reduction processing system that measures the cell stack voltage of a power extraction portion, a temperature control step for controlling the reduction processing to be performed at a temperature higher than a predetermined temperature exceeding 900 ° C., and a predetermined cell stack voltage. When the voltage of the cell stack is reached, the resistance of the base tube of the cell stack is measured, and when the resistance reaches a predetermined resistance, it is determined that the reduction process is completed assuming that the resistance of the base tube of the cell stack has reached the predetermined resistance. The reduction process end control step for ending the reduction process is provided.

The control program of the reduction treatment system according to the fourth aspect of the present invention is the case where the reduction treatment is performed on the form of the cell stack including at least one fuel cell used in the fuel cell, and the reduction treatment is performed on the at least one cell stack. A control program of a reduction processing system that measures the cell stack voltage of a power extraction portion, a temperature control step that controls the reduction processing to be performed at a temperature higher than a predetermined temperature exceeding 900 ° C., and a predetermined cell stack voltage. When the voltage of the cell stack is reached, the resistance of the base tube of the cell stack is measured, and when the resistance reaches a predetermined resistance, it is determined that the reduction process is completed assuming that the resistance of the base tube of the cell stack has reached the predetermined resistance. , The reduction process end control step for terminating the reduction process.

According to the present invention, since the completion of the reduction process is determined based on the value of the cell stack voltage of the cell stack measured by the voltage sensor, the completion of the reduction process of the cell stack can be determined easily and accurately.
Further, according to the present invention, since the temperature of the reduction furnace for performing the reduction treatment is set to a predetermined temperature exceeding 900 ° C., the reduction treatment is completed early, the reduction shortage is minimized, and the quality of the cell stack is improved. Can be made to.

It is a schematic block diagram which showed the reduction treatment system which concerns on 1st Embodiment of this invention. It is a circuit diagram of the cell stack which concerns on 1st Embodiment of this invention. It is a graph which showed the relationship between the temperature of the reduction furnace which concerns on 1st Embodiment of this invention, and the time passage of a reduction rate. It is a graph which showed the relationship between the temperature of the reduction furnace which concerns on 1st Embodiment of this invention, and the internal resistance of a cell. It shows one aspect of the cell stack in the fuel cell which concerns on one Embodiment of this invention. It shows one aspect of the SOFC module in the fuel cell which concerns on one Embodiment of this invention. It shows one aspect of the cross section of the SOFC cartridge in the fuel cell which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of a control device for a reduction treatment system, a reduction treatment system, a control method for the reduction treatment system, and a control program for the reduction treatment system according to the present invention will be described with reference to the drawings.

Here, the cell stack according to the present embodiment will be described below.
In the following, for convenience of explanation, the positional relationship of each component is specified by using the expressions “top” and “bottom” with reference to the paper, but this does not necessarily have to be the case in the vertical direction. For example, the upward direction on the paper surface may correspond to the downward direction in the vertical direction. Further, the vertical direction on the paper surface may correspond to the horizontal direction perpendicular to the vertical direction.

In the following, a cylindrical cell stack will be described as an example of a solid oxide fuel cell (SOFC) cell stack, but this is not necessarily the case. For example, a flat cell stack in which the substrate is made of a flat plate is used. There may be.

First, the cylindrical cell stack according to the present embodiment will be described with reference to FIG. Here, FIG. 5 shows one aspect of the cell stack according to the present embodiment. The cell stack 101 includes a cylindrical base tube 103, a plurality of fuel cell 105 formed on the outer peripheral surface of the base tube 103, and an interconnector 107 formed between adjacent fuel cell 105. The fuel cell 105 is formed by laminating a fuel electrode 109, a solid electrolyte 111, and an air electrode 113. Further, the cell stack 101 is attached to the air electrode 113 of the fuel cell 105 formed at one end of the plurality of fuel cell 105 formed on the outer peripheral surface of the base tube 103 in the axial direction of the base tube 103. A lead film (not shown) electrically connected to a fuel electrode 109 of a fuel cell 105 formed at the other end of the fuel cell 105, provided with a lead film 115 electrically connected via an interconnector 107. Be prepared.

Substrate tube 103 is made of a porous material, for example, CaO-stabilized _ZrO 2 (CSZ), a mixture of CSZ and nickel oxide (NiO) (CSZ + NiO) , or _Y 2 _{O 3} stabilized _ZrO 2 (YSZ), or The main component is _{MgAl 2} O _{4 and the like.} The base tube 103 supports the fuel cell 105, the interconnector 107, and the lead film 115, and the fuel supplied to the inner peripheral surface of the base tube 103 is supplied to the base tube 103 through the pores of the base tube 103. It diffuses into the fuel electrode 109 formed on the outer peripheral surface.

The fuel electrode 109 is composed of an oxide of a composite material of Ni and a zirconia-based electrolyte material, and for example, Ni / YSZ is used. The thickness of the fuel electrode 109 is 50 to 250 μm. In this case, in the fuel electrode 109, Ni, which is a component of the fuel electrode 109, has a catalytic action on the fuel gas. This catalytic action reacts a fuel gas supplied via the substrate tube 103, for example, _{a mixed gas of methane (CH 4} ) and water vapor, and _{reforms it into hydrogen (H 2} ) and carbon monoxide (CO). It is a thing. Further, the fuel electrode 109 is _{an interface between hydrogen (H 2} ) and carbon monoxide (CO) ^{obtained by reforming and oxygen ions (O 2-} ) supplied via the solid electrolyte 111 with the solid electrolyte 111. It reacts electrochemically in the vicinity to produce water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell 105 generates electricity by the electrons emitted from the oxygen ions.
The fuel gases that can be supplied and used for the SOFC fuel electrode 109 include _{hydrocarbon gases such as hydrogen (H 2} ), carbon monoxide (CO), and methane (CH ₄ ), city gas, and natural gas, as well as petroleum. Examples thereof include gas produced from carbonaceous raw materials such as methanol and coal gas by a gasification facility.

As the solid electrolyte 111, YSZ having airtightness that does not allow gas to pass through and high oxygen ion conductivity at high temperature is mainly used. ^{The solid electrolyte 111 moves oxygen ions (O2-} ) generated at the air electrode 113 to the fuel electrode 109. The film thickness of the solid electrolyte 111 located on the surface of the fuel electrode 109 is 10 to 100 μm.

The air electrode 113 is composed of, for example, a LaSrMnO _3- based oxide or a LaCoO _3- based oxide. The air electrode 113 dissociates oxygen in an oxidizing gas such as supplied air in the vicinity of the interface with the solid electrolyte 111 to generate ^{oxygen ions (O 2-).} The air electrode 113 may have a two-layer structure. In this case, the air electrode layer (air electrode intermediate layer) on the solid electrolyte 111 side is made of a material showing high ionic conductivity and excellent catalytic activity. The air electrode layer (air electrode conductive layer) on the air electrode intermediate layer may be composed of a perovskite-type oxide represented by _{Sr and Ca-doped LaMnO 3.} By doing so, the power generation performance can be further improved.

The interconnector 107 is _{composed of a conductive perovskite-type oxide represented by M 1-x} L _x TiO ₃ (M is an alkaline earth metal element and L is a lanthanoid element) such as _{SrTiO 3 system.} The interconnector 107 has a dense film so that the fuel and the oxidizing gas do not mix with each other, and has stable durability and electrical conductivity in both an oxidizing atmosphere and a reducing atmosphere.
In the adjacent fuel cell 105, the interconnector 107 electrically connects the air electrode 113 of one fuel cell 105 and the fuel electrode 109 of the other fuel cell 105, and the adjacent fuel cell 105 are connected to each other. Are connected in series.

Since the lead film 115 needs to have electron conductivity and a coefficient of thermal expansion close to that of other materials constituting the cell stack 101, Ni such as Ni / YSZ and a zirconia-based electrolyte material are used. It is composed of a composite material. The lead film 115 derives the DC power generated by the plurality of fuel cell 105s connected in series by the interconnector 107 to the vicinity of the end of the cell stack 101.

Next, the SOFC module and the SOFC cartridge according to the present embodiment will be described with reference to FIGS. 6 and 7. Here, FIG. 6 shows one aspect of the SOFC module according to the present embodiment. Further, FIG. 7 shows a cross-sectional view of one aspect of the SOFC cartridge according to the present embodiment.

As shown in FIG. 6, the SOFC module 201 includes, for example, a plurality of SOFC cartridges 203 and a pressure vessel 205 for accommodating the plurality of SOFC cartridges 203.
Although FIG. 6 illustrates a cylindrical SOFC cell stack, this is not necessarily the case, and a flat plate cell stack may be used, for example.
Further, the SOFC module 201 includes a fuel gas supply pipe 207, a plurality of fuel gas supply branch pipes 207a, a fuel gas discharge pipe 209, and a plurality of fuel gas discharge branch pipes 209a. Further, the SOFC module 201 includes an oxidizing gas supply pipe (not shown), an oxidizing gas supply branch pipe (not shown), an oxidizing gas discharge pipe (not shown), and a plurality of oxidizing gas discharge branches (not shown). To be equipped.

The fuel gas supply pipe 207 is provided outside the pressure vessel 205, is connected to a fuel supply unit that supplies fuel having a predetermined gas composition and a predetermined flow rate according to the amount of power generated by the SOFC module 201, and a plurality of fuel gases. It is connected to the supply branch pipe 207a. The fuel gas supply pipe 207 branches and guides a predetermined flow rate of fuel supplied from the fuel supply unit described above to a plurality of fuel gas supply branch pipes 207a. Further, the fuel gas supply branch pipe 207a is connected to the fuel gas supply pipe 207 and is also connected to a plurality of SOFC cartridges 203. The fuel gas supply branch pipe 207a guides the fuel supplied from the fuel gas supply pipe 207 to the plurality of SOFC cartridges 203 at a substantially equal flow rate, and substantially equalizes the power generation performance of the plurality of SOFC cartridges 203.

The fuel gas discharge branch pipe 209a is connected to a plurality of SOFC cartridges 203 and is also connected to the fuel gas discharge pipe 209. The fuel gas discharge branch pipe 209a guides the exhaust fuel discharged from the SOFC cartridge 203 to the fuel gas discharge pipe 209. Further, the fuel gas discharge pipe 209 is connected to a plurality of fuel gas discharge branch pipes 209a, and a part of the fuel gas discharge pipe 209 is arranged outside the pressure vessel 205. The fuel gas discharge pipe 209 guides the exhaust fuel derived from the fuel gas discharge branch pipe 209a at a substantially equal flow rate to the outside of the pressure vessel 205.

Since the pressure vessel 205 is operated at an internal pressure of 0.1 MPa to about 1 MPa and an internal temperature of atmospheric temperature to about 550 ° C., it has a proof stress and corrosion resistance against an oxidizing agent such as oxygen contained in an oxidizing gas. The material you have is used. For example, a stainless steel material such as SUS304 is suitable.

Here, in the present embodiment, a mode in which a plurality of SOFC cartridges 203 are assembled and stored in the pressure vessel 205 will be described, but the present invention is not limited to this, and for example, the SOFC cartridge 203 is not assembled and the pressure is increased. It can also be stored in the container 205.

As shown in FIG. 7, the SOFC cartridge 203 includes a plurality of cell stacks 101, a power generation chamber 215, a fuel gas supply chamber 217, a fuel gas discharge chamber 219, an oxidizing gas supply chamber 221 and an oxidizing gas discharge chamber. It is equipped with 223. Further, the SOFC cartridge 203 includes an upper tube plate 225a, a lower tube plate 225b, an upper heat insulating body 227a, and a lower heat insulating body 227b. In the present embodiment, in the SOFC cartridge 203, the fuel gas supply chamber 217, the fuel gas discharge chamber 219, the oxidizing gas supply chamber 221 and the oxidizing gas discharge chamber 223 are arranged as shown in FIG. , The structure is such that the fuel and the oxidizing gas flow toward the inside and the outside of the cell stack 101, but this is not always necessary, for example, the inside and the outside of the cell stack flow in parallel, or The oxidizing gas may flow in a direction orthogonal to the longitudinal direction of the cell stack.

The power generation chamber 215 is a region formed between the upper heat insulating body 227a and the lower heat insulating body 227b. The power generation chamber 215 is a region in which the fuel cell 105 of the cell stack 101 is arranged, and is a region in which fuel and an oxidizing gas are electrochemically reacted to generate electricity. Further, the temperature in the vicinity of the central portion of the cell stack 101 in the longitudinal axis direction of the power generation chamber 215 is monitored by a temperature sensor or the like, and becomes a high temperature atmosphere of about 700 ° C. to 1000 ° C. during steady operation of the SOFC module 201.

The fuel gas supply chamber 217 is an area surrounded by the upper casing 229a and the upper pipe plate 225a of the SOFC cartridge 203, and the fuel gas supply branch pipe 207a is provided by the fuel gas supply hole 231a provided in the upper part of the upper casing 229a. Is communicated with. The plurality of cell stacks 101 are joined to the upper pipe plate 225a by the seal member 237a, and the fuel gas supply chamber 217 supplies a plurality of fuels supplied from the fuel gas supply branch pipe 207a through the fuel gas supply hole 231a. It is guided to the inside of the base tube 103 of the cell stack 101 at a substantially uniform flow rate, and the power generation performance of the plurality of cell stacks 101 is made substantially uniform.

The fuel gas discharge chamber 219 is an area surrounded by the lower casing 229b and the lower pipe plate 225b of the SOFC cartridge 203, and communicates with the fuel gas discharge branch pipe 209a by the fuel gas discharge hole 231b provided in the lower casing 229b. Has been done. The plurality of cell stacks 101 are joined by a lower pipe plate 225b and a sealing member 237b, and the fuel gas discharge chamber 219 passes through the inside of the base pipe 103 of the plurality of cell stacks 101 and is supplied to the fuel gas discharge chamber 219. The exhaust fuel to be generated can be aggregated and guided to the fuel gas discharge branch pipe 209a through the fuel gas discharge hole 231b.

Oxidizing gas having a predetermined gas composition and a predetermined flow rate is branched into an oxidizing gas supply branch pipe according to the amount of power generated by the SOFC module 201, and is supplied to a plurality of SOFC cartridges 203. The oxidizing gas supply chamber 221 is a region surrounded by the lower casing 229b, the lower pipe plate 225b, and the lower heat insulating body 227b of the SOFC cartridge 203, and is provided by the oxidizing gas supply hole 233a provided on the side surface of the lower casing 229b. , It communicates with an oxidizing gas supply branch pipe (not shown). The oxidizing gas supply chamber 221 transfers an oxidizing gas having a predetermined flow rate supplied from an oxidizing gas supply branch pipe (not shown) through the oxidizing gas supply hole 233a to the power generation chamber 215 via the oxidizing gas supply gap 235a. It can be derived with a substantially uniform flow rate.

The oxidizing gas discharge chamber 223 is an area surrounded by the upper casing 229a, the upper pipe plate 225a, and the upper heat insulating body 227a of the SOFC cartridge 203, and is provided by the oxidizing gas discharge holes 233b provided on the side surface of the upper casing 229a. , It communicates with an oxidizing gas discharge branch pipe (not shown). The oxidizing gas discharge chamber 223 oxidizes the exhaust air supplied from the power generation chamber 215 to the oxidizing gas discharge chamber 223 through the oxidizing gas discharge gap 235b through the oxidizing gas discharge hole 233b (not shown). It can be led to a gas discharge branch pipe.

In the upper casing 225a, the upper casing 229a is provided so that the top plate of the upper casing 229a and the top plate of the upper casing 229a and the upper heat insulating body 227a are substantially parallel to each other between the top plate of the upper casing 229a and the upper heat insulating body 227a. It is fixed to the side plate of. Further, the upper tube plate 225a has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The upper tube plate 225a airtightly supports one end of the plurality of cell stacks 101 via either one or both of the sealing member and the adhesive member, and the fuel gas supply chamber 217 and the oxidizing gas discharge chamber 223. It is to isolate and.

The lower tube plate 225b is attached to the side plate of the lower casing 229b so that the bottom plate of the lower tube plate 225b, the bottom plate of the lower casing 229b, and the lower heat insulating body 227b are substantially parallel between the bottom plate of the lower casing 229b and the lower heat insulating body 227b. It is fixed. Further, the lower tube plate 225b has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The lower tube plate 225b airtightly supports the other end of the plurality of cell stacks 101 via one or both of the sealing member and the adhesive member, and the fuel gas discharge chamber 219 and the oxidizing gas supply chamber 221. It is to isolate and.

The upper heat insulating body 227a is arranged at the lower end of the upper casing 229a so that the upper heat insulating body 227a, the top plate of the upper casing 229a, and the upper tube plate 225a are substantially parallel to each other, and is fixed to the side plate of the upper casing 229a. There is. Further, the upper heat insulating body 227a is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of this hole is set to be larger than the outer diameter of the cell stack 101. The upper heat insulating body 227a includes an oxidizing gas discharge gap 235b formed between the inner surface of the hole and the outer surface of the cell stack 101 inserted through the upper heat insulating body 227a.

The upper heat insulating body 227a separates the power generation chamber 215 and the oxidizing gas discharge chamber 223, and the atmosphere around the upper pipe plate 225a becomes high in temperature, resulting in a decrease in strength and corrosion by the oxidizing agent contained in the oxidizing gas. Suppress the increase. The upper tube plate 225a and the like are made of a metal material having high temperature durability such as Inconel, but the upper tube plate 225a and the like are exposed to the high temperature in the power generation chamber 215 and the temperature difference in the upper tube plate 225a and the like becomes large. It prevents thermal deformation. Further, the upper heat insulating body 227a guides the oxidative gas that has passed through the power generation chamber 215 and exposed to high temperature to the oxidative gas discharge chamber 223 by passing through the oxidative gas discharge gap 235b.

According to the present embodiment, due to the structure of the SOFC cartridge 203 described above, the fuel and the oxidizing gas flow toward the inside and the outside of the cell stack 101. As a result, the oxidative gas exchanges heat with the fuel supplied to the power generation chamber 215 through the inside of the base tube 103, and the upper tube plate 225a and the like made of a metal material are deformed such as buckling. It is cooled to a temperature that does not allow it to be supplied to the oxidizing gas discharge chamber 223. Further, the fuel is heated by heat exchange with the oxidative gas discharged from the power generation chamber 215 and supplied to the power generation chamber 215. As a result, the fuel that has been preheated to a temperature suitable for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

The lower heat insulating body 227b is arranged at the upper end of the lower casing 229b so that the bottom plate of the lower heat insulating body 227b, the bottom plate of the lower casing 229b, and the lower pipe plate 225b are substantially parallel to each other, and is fixed to the side plate of the lower casing 229b. .. Further, the lower heat insulating body 227b is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of this hole is set to be larger than the outer diameter of the cell stack 101. The lower heat insulating body 227b includes an oxidizing gas supply gap 235a formed between the inner surface of the hole and the outer surface of the cell stack 101 inserted through the lower heat insulating body 227b.

The lower heat insulating body 227b separates the power generation chamber 215 and the oxidizing gas supply chamber 221, and the atmosphere around the lower pipe plate 225b becomes high in temperature, resulting in a decrease in strength and corrosion by the oxidizing agent contained in the oxidizing gas. Suppress the increase. The lower tube plate 225b or the like is made of a metal material having high temperature durability such as Inconel, but the lower tube plate 225b or the like is exposed to a high temperature and the temperature difference in the lower tube plate 225b or the like becomes large, so that the lower tube plate 225b or the like is thermally deformed. It is something to prevent. Further, the lower heat insulating body 227b guides the oxidizing gas supplied to the oxidizing gas supply chamber 221 to the power generation chamber 215 through the oxidizing gas supply gap 235a.

According to the present embodiment, due to the structure of the SOFC cartridge 203 described above, the fuel and the oxidizing gas flow toward the inside and the outside of the cell stack 101. As a result, the exhaust fuel that has passed through the inside of the base pipe 103 and passed through the power generation chamber 215 is heat-exchanged with the oxidizing gas supplied to the power generation chamber 215, and the lower pipe plate 225b made of a metal material or the like is exchanged. Is cooled to a temperature at which it does not deform such as buckling and is supplied to the fuel gas discharge chamber 219. Further, the oxidizing gas is heated by heat exchange with the exhaust fuel and supplied to the power generation chamber 215. As a result, the oxidizing gas heated to the temperature required for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

The DC power generated in the power generation chamber 215 is led out to the vicinity of the end of the cell stack 101 by a lead film 115 made of Ni / YSZ or the like provided in the plurality of fuel cell 105, and then the current collecting rod of the SOFC cartridge 203 (not). Electric power is collected through a current collecting plate (not shown) on the (shown), and is taken out to the outside of each SOFC cartridge 203. The DC power derived to the outside of the SOFC cartridge 203 by the current collector rod connects the generated power of each SOFC cartridge 203 to a predetermined number of series and parallel numbers, and is led out to the outside of the SOFC module 201. It is converted into a predetermined AC power by a power conversion device (inverter or the like) such as a power conditioner (not shown) and supplied to a power supply destination (for example, a load facility or a power system).

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.
FIG. 1 shows a schematic configuration of a reduction treatment system according to the present embodiment.
As shown in FIG. 1, the reduction processing system 1 includes a reduction furnace 10, a control device 50, and a voltage sensor 30 as main configurations.
The reduction furnace 10 accommodates one to a plurality of cell stacks 101 in the reduction furnace 10 and performs a reduction process. However, in FIG. 1, only one cell stack 101 is shown for convenience, and the cell stack 101 is vertically above the cell stack 101. The portion and the lower portion are each supported by a support plate 80 so as to allow thermal expansion.
As an example, the cell stack 101 in the present embodiment mainly comprises a cylindrical base tube 103, a fuel cell 105 formed on the outer peripheral surface of the base tube 103, and a lead film 115. I have. Here, the cell stack 101 is an object to be reduced by the reduction processing system 1, and does not constitute the reduction processing system 1.
In the present embodiment, the voltage sensor 30 is connected to the air poles 113 of each fuel cell 105 formed at both ends of the cell stack 101 as a power extraction portion of the cell stack 101, and is formed in the cell stack 101. It is installed so as to measure the cell stack voltage, which is the voltage of all the fuel cell 105.
The control device 50 is connected to the reduction furnace 10 and the voltage sensor 30, and controls the temperature of the reduction furnace 10, acquires the cell stack voltage measured by the voltage sensor 30, controls the reduction process, and the like.

The control device 50 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a computer-readable storage medium, and the like. Then, as an example, a series of processes for realizing various functions are stored in a storage medium or the like in the form of a program, and the CPU reads this program into a RAM or the like to execute information processing / arithmetic processing. As a result, various functions are realized. The program is installed in a ROM or other storage medium in advance, is provided in a state of being stored in a computer-readable storage medium, or is distributed via a wired or wireless communication means. Etc. may be applied. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, and the like.

A reducing gas is supplied to the reduction furnace 10 from an external reducing gas supply source (not shown), and the reducing gas is guided into the cell stack 101. Further, the reducing gas discharged from the inside of the other end of the cell stack 101 is discharged to the outside of the reduction furnace 10. The reducing gas is used to reduce the cell stack 101. The reducing gas, e.g., hydrogen _{(H 2)} gas for about 20 vol% to 50 vol% and nitrogen _{(N 2)} gas mixture of about 80 vol% to 50 vol% of gas is used. By diluting the hydrogen gas with nitrogen gas to reduce the partial pressure of hydrogen, the reduction reaction of the cell stack 101 is prevented from proceeding rapidly, and the reduction of the air electrode 113 is suppressed. The cell stack 101 is reduced by being housed in the reduction furnace 10 of the reduction processing system 1 and reacting with the reducing gas.
An oxidizing gas such as air (not shown) is supplied to the outside of the cell stack 101 around the cell stack 101, and the discharged oxidizing gas is discharged to the outside of the reduction furnace 10. The flow rate of the oxidizing gas may be a small flow rate as long as the temperature distribution in the furnace can be maintained and the electromotive force (described later) of the cell stack 101 can be confirmed, or the flow rate is maintained when the cell stack 101 is housed in the reduction furnace 10. The air in the reduction furnace may be used as it is.

Further, the reduction furnace 10 is provided with a heater (not shown), and the temperature at the center of the cell stack 101 is set based on the temperature detected by the temperature sensors (not shown) arranged around the cell stack 101. Control. The reduction reaction of the cell stack 101 is controlled by the control device 50 so that the temperature at the center of the cell stack 101 is 930 ° C. or higher, preferably 930 ° C. to 1000 ° C., more preferably 950 ° C., and the cell at this time. Both ends of the stack 101 have a temperature lower than the temperature of the central portion of the cell stack 101 due to the heating temperature distribution of the reduction furnace 10 and the introduction of the reducing gas in consideration of the heat resistance of the portion that supports and holds the cell stack 101. Therefore, the temperature of both ends of the cell stack 101 is controlled by the control device 50 so as to be 600 ° C. to 700 ° C., preferably 600 ° C.

[Relationship between cell stack reduction processing and voltage]
Next, the relationship between the reduction process of the cell stack 101 and the voltage will be described with reference to FIG. 2 based on the voltage, current, and resistance of the cell stack 101.
FIG. 2 is a circuit diagram of the cell stack 101 of the first embodiment.

As shown in FIG. 2, when the reduction process of the cell stack 101 is nearing completion, the internal resistance of the fuel electrode 109 is small, so that the electromotive force of the cell stack 101 is the theoretical voltage value of the cell stack 101. , The sum of the voltage drop due to the cell internal resistance, electrolyte resistance and substrate tube resistance. As for the electromotive force of the cell stack 101, the theoretical electromotive force in thermodynamic equilibrium is derived from the Nernst equation as a function of the partial pressure of the reaction gas and the temperature. The theoretical voltage value Vt is derived and set as the theoretical electromotive force minus the influence of the voltage drop due to the supply and diffusion of the reaction gas, and the electromotive force V is derived from the electrical resistance loss of the cell stack 101. be able to. That is, the electromotive force V of the cell stack 101 is as follows (1), where Vt is the theoretical voltage value of the cell stack 101, i is the current, Rc is the internal resistance of the cell, Re is the electrolyte resistance, and Rb is the resistance of the substrate tube 103. ) Is expressed by the formula.

V = Vt-i (Rc + (ReRb) / (Re + Rb)) (1)

In the reduction treatment, the fuel electrode 109 is reduced to NiO and the NiO contained in the substrate pipe 103 is reduced to Ni. If the reduction process is nearing completion but the reduction is not sufficiently completed, most of the fuel electrode 109 is reduced to Ni and a current path is secured, so that even if there is residual NiO. Since the internal resistance is sufficiently small, it is difficult to confirm the completion of the reduction treatment by changing the internal resistance value of the fuel electrode 109. On the other hand, it was found that the resistance Rb of the substrate tube 103 was not in an insulated state, and the resistance Rb was at a small value. This is because, for example, since the substrate tube 103 is _{a mixture of CaO-stabilized ZrO 2} and NiO, the distance between the particles of NiO in the substrate tube is short in a state where the reduction treatment is not sufficiently performed, so that the substrate tube 103 This is because the resistance Rb of As a result, a current (leakage current) flows through the substrate tube 103. As the reduction treatment progresses, the NiO particles in the substrate tube 103 are separated from each other, so that the distance between the Ni particles becomes wider, and the resistance Rb of the substrate tube 103 gradually increases, so that the completion of the reduction treatment can be judged with high accuracy. It is possible. When the resistance Rb of the base tube 103 becomes a predetermined resistance, the electromotive force V of the cell stack 101, that is, the cell stack voltage measured by the voltage sensor 30 becomes a predetermined voltage, and the control device 50 determines that the reduction process is completed. Judgment is made, and the reduction process is completed. For a predetermined voltage, for example, 95% of the theoretical electromotive force of the cell stack 101 is set, but this value can be changed as appropriate.
Here, the voltage sensor 30 is installed in at least one predetermined cell stack 101 among the plurality of cell stacks 101 housed in the reduction furnace 10, and the cell stack voltage measured by all the voltage sensors 30 is predetermined. When the voltage is reached, it is judged that the reduction process is completed.

Further, by reducing the temperature inside the reduction furnace 10 at a temperature higher than the temperature of the conventional reduction treatment apparatus (for example, 900 ° C.), the temperature of the cell stack 101 rises, so that the cell internal resistance Rc and the electrolyte resistance Re Is reduced, and the electrolyte resistance Re is particularly significantly reduced. As a result, even when the difference in the change in the resistance Rb of the substrate tube 103 is small, the current (leakage current) flowing through the substrate tube 103 is transferred to the electromotive force V of the cell stack 101 as shown in equation (1). It can be detected with high sensitivity depending on the value. Therefore, the completion of the reduction process can be detected more accurately from the value of the cell stack voltage measured by the voltage sensor 30.

[Difference in reduction state depending on the temperature of the reduction furnace]
FIG. 3 is a graph showing the relationship between the temperature of the reduction furnace according to the first embodiment of the present invention and the passage of time of the reduction rate.
In the figure, the vertical axis represents the reduction rate of the cell stack 101, and the horizontal axis represents time. The reduction rate indicates the rate at which NiO is reduced to Ni.
When the temperature inside the reduction furnace 10 is 900 ° C. used in the conventional reduction treatment apparatus, the reduction rate gradually increases with time as shown by the dotted line in FIG. In the conventional reduction processing apparatus that performs reduction processing in units of cartridges, the temperature of the cell stack 101 incorporated in the cartridge is controlled. Therefore, in order to suppress the increase in the temperature distribution of the cell stack 101, the temperature at the central portion of the cell stack 101 is limited to be raised to about 900 ° C. Further, in the case of the conventional reduction treatment apparatus that performs reduction treatment in units of cartridges, there is a limit to the temperature rise due to heat generation during reduction due to the limit temperature of the metal part of the seal portion.
Further, the reduction treatment at the limit temperature of 900 ° C. was interpreted as a sufficiently fast treatment speed, and there was no need to shorten the reduction treatment time.
Here, if the metal oxide used in the cell stack 101 is nickel oxide _(N i O), by a nickel oxide _(N i O) and hydrogen _{(H 2)} is a reduction reaction of nickel _(N i) And water (H ₂ O) is produced.

On the other hand, in the present embodiment, unlike the conventional reduction processing apparatus, the cell stack 101 before being incorporated into the cartridge is targeted for processing, and a plurality of cells are carried into the reduction furnace 10 in units of the cell stack 101 to perform reduction processing. 10 is adopted. By carrying it into the reduction furnace 10 in the form of the cell stack 101 and holding it, the influence of heat generation in the furnace is small, the heat transfer characteristics to the cell stack 101 are improved, and the reduction treatment temperature can be raised. .. Therefore, when the reduction treatment was performed at 950 ° C., which is a higher temperature than before, it was found that the reduction rate reached around 100% faster than the case of 900 ° C. as shown by the solid line in FIG. This is because the reaction between NiO and H ₂ is promoted reduction to Ni was easily proceeds.

[Temperature setting of reduction furnace]
FIG. 4 is a graph showing the relationship between the temperature of the reduction furnace and the resistance inside the cell according to the first embodiment of the present invention.
In the figure, the vertical axis represents the electrolyte resistance Re (Ω · cm), the horizontal axis represents the temperature (° C.) of the reduction furnace 10, and changes in the electrolyte resistance Re due to temperature are plotted in 10 ° C. increments. As shown in FIG. 4, when the temperature of the reduction furnace 10 rises, the electrolyte resistance Re decreases, but when the temperature of the reduction furnace 10 exceeds a certain level, the decrease in the electrolyte resistance Re becomes saturated. In the present embodiment, the region where the slope of the temperature change of the electrolyte resistance Re shown in FIG. 4 is −0.1 Ω · cm / 10 ° C. or more (the absolute value of the slope is 0.1 Ω · cm / 10 ° C. or less) is defined. It is defined that the decrease in electrolyte resistance Re is saturated. From FIG. 4, the predetermined temperature for the reduction treatment at which the slope of the temperature change of the electrolyte resistance Re is −0.1 Ω · cm / 10 ° C. or higher is 930 ° C. Further, it can be said that the change in the resistance value of the cell internal resistance Rc is small but has the same tendency. The slope of the temperature change of the electrolyte resistor Re is calculated, for example, in increments of 10 ° C.
The slope X of the temperature change of the electrolyte resistance Re is given by the following equation (2) _{, where Re (t) is the electrolyte resistance at the temperature t and Re (t-10)} is the electrolyte resistance at the temperature t-10. expressed.

X = (Re _(t) -Re _(t-10) ) / (t- (t-10)) (2)

Therefore, by setting the predetermined temperature of the reduction furnace 10 to 930 ° C. or higher, it can be considered that the decrease in the cell internal resistance Rc and the electrolyte resistance Re approaches saturation, that is, approaches a constant value. As a result, whether or not the reduction treatment of the cell stack 101 is completed can be determined by increasing the resistance Rb of the base tube 103 to a predetermined resistance, but only the resistance Rb component of the base tube 103 is separated and extracted. It is necessary to make such measurements. Therefore, in the present embodiment, it is possible to determine whether or not the reduction process is completed when the electromotive force V of the cell stack 101, that is, the cell stack voltage reaches a predetermined voltage, using the equation (1). I did.

As described above, the control device of the reduction treatment system, the reduction treatment system, the control method of the reduction treatment system, and the control program of the reduction treatment system according to the present embodiment have the following effects.
According to the present embodiment, by performing the reduction treatment of the cell stack 101 at a temperature equal to or higher than a predetermined temperature exceeding 900 ° C., which is a higher temperature than the conventional one, the reduction treatment of the cell stack 101 is further higher than the conventional one in a shorter time. While advancing to the reduction rate, it is possible to detect the end of the reduction process with high accuracy and judge the completion.
As a result, the reduction treatment of the cell stack 101 is advanced to a higher reduction rate than before, so that the reduction shortage can be minimized and the quality of the cell stack 101 can be improved.
Further, by performing the reduction treatment at a temperature higher than a predetermined temperature exceeding 900 ° C., which is a higher temperature than before, the reduction reaction of the metal oxide is promoted and the reduction is likely to proceed. Therefore, the reduction treatment is terminated early. , Productivity can be improved.
Further, when the reduction treatment of the cell stack 101 is performed at a temperature higher than a predetermined temperature exceeding 900 ° C., which is a higher temperature than the conventional one, the cell internal resistance Rc and the electrolyte resistance Re are lowered, so that the resistance Rb of the base tube 103 is reduced. The change has a relatively large effect and can be easily determined, and the change in the current (leakage current) flowing through the substrate tube 103 can be detected accurately by the cell stack voltage. Here, by reducing the metal oxide (for example, nickel oxide) contained in the cell stack 101, the resistance Rb of the substrate tube 103 increases and the leakage current decreases as the reduction of the substrate tube 103 progresses. As a result, it is possible to determine whether or not the reduction process is completed based on the value of the cell stack voltage.
Further, since it is determined whether or not the reduction process is completed based on whether or not the cell stack voltage has reached a predetermined voltage, it is possible to easily determine the completion of the reduction process of the cell stack 101.

Further, according to the present embodiment, since the completion of the reduction process is determined based on whether or not the cell stack voltage reaches 95% or more of the theoretical electromotive force of the fuel cell 105, the reduction state of the base tube 103 is correctly determined. It is possible to manage and accurately determine the completion of the reduction process.

Further, according to the present embodiment, the voltage sensor 30 is installed in the predetermined cell stack 101, and when all the voltages in the predetermined cell stack reach the predetermined voltage, it is determined that the reduction process is completed. It is possible to suppress variations in the reduction treatment in the furnace 10 and more accurately determine the completion of the reduction treatment.

[Second Embodiment]
Hereinafter, the second embodiment of the present invention will be described.
In the first embodiment described above, it is determined that the reduction is completed when the cell stack voltage reaches a predetermined voltage, but in the present embodiment, in addition to this, the resistance of the substrate tube further reaches a predetermined resistance. Is used to determine the completion of reduction. Since other points are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and the description thereof will be omitted.

When the cell stack voltage measured by the voltage sensor 30 reaches a predetermined voltage, for example, the control device 50 measures the resistance Rb of the substrate tube 103. Since the resistance of the substrate tube 103 reaches a predetermined resistance Rb when the reduction treatment is completed, the control device 50 does not measure and evaluate the momentary change in the value of the resistance Rb, but the control device 50 measures it. When the resistance Rb of the substrate tube 103 is equal to or higher than the predetermined resistance, it is determined that the reduction treatment is completed. Here, for example, 10 MΩ to 100 MΩ is set as a predetermined resistor. Since it is similar to determining whether or not the resistance is in an insulated state from the measurement range of the resistance measuring instrument, the predetermined resistance may be set to, for example, 50 MΩ or more.
When the resistance Rb of the base tube 103 is less than the predetermined resistance, instead of measuring and evaluating the resistance value change in units of several kΩ, the resistance Rb of the base tube 103 is continuously reduced until the resistance Rb becomes the predetermined resistance or more. Perform processing.

As described above, the control device of the reduction treatment system, the reduction treatment system, the control method of the reduction treatment system, and the control program of the reduction treatment system according to the present embodiment have the following effects.
According to the present embodiment, the resistance Rb of the base tube 103 of the cell stack 101 is measured, and when the predetermined resistance is reached, the reduction process is terminated. Therefore, in addition to the voltage monitoring, the resistance Rb of the base tube 103 is also used for determination. It is possible to more accurately determine the completion of the reduction treatment.

Further, according to the present embodiment, since the completion of the reduction treatment is determined by whether or not the resistance Rb of the substrate tube 103 has reached 10 MΩ to 100 MΩ, it is possible to correctly manage the reduced state of the substrate tube 103. Yes, it is possible to accurately judge the completion of the reduction process.

Although each embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes within a range that does not deviate from the gist of the present invention. ..

For example, in each of the above-described embodiments, the voltage sensor is installed in a predetermined cell stack, but it may be installed in all cell stacks.

1 Reduction processing system 10 Reduction furnace 30 Voltage sensor 50 Control device 101 Cell stack 103 Base tube 105 Fuel cell cell 107 Interconnect 109 Fuel pole 111 Solid electrolyte 113 Air pole 115 Lead film (power extraction part)
201 SOFC module 203 SOFC cartridge 205 Pressure vessel 207 Fuel gas supply pipe 207a Fuel gas supply branch pipe 209 Fuel gas discharge pipe 209a Fuel gas discharge branch pipe 215 Power generation room 217 Fuel gas supply room 219 Fuel gas discharge room 221 Oxidizing gas supply room 221 223 Oxidizing gas discharge chamber 225a Upper tube plate 225b Lower tube plate 227a Upper heat insulating body 227b Lower heat insulating body 229a Upper casing 229b Lower casing 231a Fuel gas supply hole 231b Fuel gas discharge hole 233a Oxidizing gas supply hole 233b Oxidizing gas discharge hole 235a Oxidizing gas supply gap 235b Oxidizing gas discharge gap 237a, 237b Sealing member

Claims (10)

A reduction furnace that reduces the form of a cell stack containing at least one fuel cell used in a fuel cell, and a reduction furnace.
A voltage sensor that measures the cell stack voltage of at least one power extraction portion of the cell stack, and
It is a control device of the reduction processing system equipped with
The reduction furnace is controlled to perform the reduction treatment at a temperature equal to or higher than a predetermined temperature exceeding 900 ° C.
When the cell stack voltage reaches a predetermined voltage, the resistance of the base tube of the cell stack is measured, and when the resistance reaches the predetermined resistance, it is assumed that the resistance of the base tube of the cell stack reaches the predetermined resistance, and the reduction treatment is performed. A control device for a reduction processing system that determines that the process has been completed and controls the end of the reduction processing. The control device for the reduction treatment system according to claim 1, wherein the predetermined temperature of the reduction treatment of the reduction furnace is equal to or higher than a temperature at which the slope of the temperature change of the electrolyte resistance is −0.1 Ω · cm / 10 ° C. or higher. The control device for a reduction treatment system according to claim 1, wherein the predetermined temperature of the reduction treatment in the reduction furnace is 930 ° C. or higher. The invention according to any one of claims 1 to 3, wherein when the cell stack voltage reaches 95% or more of the theoretical electromotive force of the fuel cell, it is determined that the reduction process is completed, and control is performed to end the reduction process. Control device for the reduction processing system. The voltage sensor is installed in a predetermined cell stack among the plurality of the cell stacks, and the reduction process is completed when all the cell stack voltages measured by the voltage sensors reach a predetermined voltage. The control device for a reduction processing system according to any one of claims 1 to 4, which determines and controls the termination of the reduction processing. The reduction treatment system according to any one of claims 1 to 5, which controls the termination of the reduction treatment when the resistance of the substrate tube of the cell stack reaches a predetermined resistance value of 10 MΩ to 100 MΩ. Control device. The control device for a reduction treatment system according to any one of claims 1 to 6 , wherein the fuel cell is a solid oxide fuel cell. The control device according to any one of claims 1 to 7.
A reduction furnace that performs reduction processing on the form of a cell stack in which a plurality of fuel cell cells used for a fuel cell are connected in series,
A voltage sensor that measures the cell stack voltage of the power extraction portion of the cell stack, and
Reduction processing system equipped with. When the reduction treatment is performed on the form of a cell stack containing at least one fuel cell used for a fuel cell.
A control method for a reduction processing system that measures the cell stack voltage of at least one power extraction portion of the cell stack.
A temperature control step for controlling the reduction treatment to be performed at a temperature equal to or higher than a predetermined temperature exceeding 900 ° C.
When the cell stack voltage reaches a predetermined voltage, the resistance of the base tube of the cell stack is measured, and when the resistance reaches the predetermined resistance, it is assumed that the resistance of the base tube of the cell stack reaches the predetermined resistance, and the reduction treatment is performed. The reduction process end control step, which determines that the process has been completed, and ends the reduction process.
A control method for a reduction processing system equipped with. When the reduction treatment is performed on the form of a cell stack containing at least one fuel cell used for a fuel cell.
A control program for a reduction processing system that measures the cell stack voltage of at least one power extraction portion of the cell stack.
A temperature control step for controlling the reduction treatment to be performed at a temperature higher than a predetermined temperature exceeding 900 ° C.
When the cell stack voltage reaches a predetermined voltage, the resistance of the base tube of the cell stack is measured, and when the resistance reaches the predetermined resistance, it is assumed that the resistance of the base tube of the cell stack reaches the predetermined resistance, and the reduction treatment is performed. The reduction process end control step of determining that the process has been completed and ending the reduction process, and
Control program of the reduction processing system equipped with.

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