JP2022131744A - Fuel cell temperature evaluation device, control device, and temperature evaluation method - Google Patents

Abstract

To continuously evaluate a power generation chamber temperature of a fuel cell over a long period of time while suppressing an increase in maintenance costs.SOLUTION: A fuel cell temperature evaluation device stores, in a storage unit, a characteristic map showing the difference between the initial internal heat generation amount and the internal heat generation amount at the time of temperature estimation, and the correlation between the fuel cell and a power generation chamber temperature. Then, on the basis of the characteristic map stored in the storage unit, evaluation is performed by calculating the power generation chamber temperature corresponding to the calculation result of the difference in the internal heat generation amount of the fuel cell.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a fuel cell temperature evaluation device, a control device, and a temperature evaluation method.

A fuel cell that generates power by chemically reacting a fuel gas and an oxidizing gas has characteristics such as excellent power generation efficiency and environmental friendliness. Among these, solid oxide fuel cells (Solid Oxide Fuel Cells: SOFC) use ceramics such as zirconia ceramics as electrolytes, and hydrogen, city gas, natural gas, petroleum, methanol, and carbon-containing raw materials are used in gasification equipment. A gas such as gasification gas produced by is supplied as a fuel gas, and is reacted in a high-temperature atmosphere to generate power.

A fuel cell comprises, for example, a fuel cell cartridge having a generator chamber containing a plurality of fuel cells. In the solid oxide fuel cell described above, the proper temperature of the generation chamber is 700° C. to 1000° C., and it is necessary to appropriately monitor the temperature during operation of the fuel cell. For example, in Patent Document 1, a thermocouple, which is a temperature sensor, is installed at a temperature measurement portion of the fuel cell inside the power generation chamber, and the temperature of the power generation chamber is monitored by acquiring the detected value. Further, in Patent Document 2, a device having a cell state calculation unit that calculates the maximum temperature of each fuel cell from the temperature and flow rate of the fuel gas, the temperature and flow rate of the oxidant gas, and the current value of the current taken out from the fuel cell stack is disclosed. disclosed.

Japanese Patent Laid-Open No. 2019-185853 Japanese Patent Application Laid-Open No. 2015-103442

In Patent Literature 1, the temperature of the generating chamber is monitored by installing a thermocouple, which is a temperature sensor, at a temperature measuring portion located inside the generating chamber. Such thermocouples generally have a durability of several years, which is shorter than that of fuel cells, which are being developed with a goal of durability of about 10 years. In particular, the generator chamber in which the thermocouples are arranged has a high temperature and is a harsh environment for the thermocouples. Therefore, in order to continuously monitor the temperature of the generating chamber of the fuel cell, it is necessary to replace the thermocouple, which may increase the maintenance cost of the fuel cell.

In addition, in Patent Document 2, since the maximum temperature of the fuel cell is obtained from the temperature and flow rate of the supplied fuel gas and oxidant gas and the current value taken out from the stack, the influence of the increase in the amount of heat generated due to the change in the performance of the stack is taken into consideration. not.

At least one embodiment of the present disclosure has been devised in view of the above circumstances, and is a fuel cell temperature evaluation device and control device capable of continuously evaluating the temperature of the generation chamber of a fuel cell over a long period of time while suppressing an increase in maintenance costs. An object is to provide an apparatus and a temperature evaluation method.

In order to solve the above problems, a fuel cell temperature evaluation device according to at least one embodiment of the present disclosure includes:
an internal calorific value difference calculator for calculating the difference between the initial internal calorific value of the fuel cell and the internal calorific value at the time of temperature estimation;
a storage unit for storing a characteristic map indicating the correlation between the difference in the internal heat generation amount and the temperature of the generation chamber of the fuel cell;
a generator chamber temperature calculator for calculating the generator chamber temperature corresponding to the difference in the internal calorific value calculated by the internal calorific value difference calculator, based on the characteristic map stored in the storage unit;
Prepare.

In order to solve the above problems, a fuel cell control device according to at least one embodiment of the present disclosure includes:
a fuel cell temperature evaluation device according to at least one embodiment of the present disclosure;
a controller for controlling the fuel cell based on the generator chamber temperature calculated by the generator chamber temperature calculator;
Prepare.

In order to solve the above problems, a fuel cell temperature evaluation method according to at least one embodiment of the present disclosure includes:
a step of calculating a difference between an initial internal calorific value of the fuel cell and an internal calorific value at the time of temperature estimation;
calculating the temperature of the power generation chamber corresponding to the difference in the amount of internal heat generation based on a characteristic map showing the correlation between the difference in the amount of internal heat generation and the temperature of the generation chamber of the fuel cell;
Prepare.

According to at least one embodiment of the present disclosure, a fuel cell temperature evaluation device, a control device, and a temperature evaluation method capable of continuously evaluating the generation chamber temperature of a fuel cell over a long period of time while suppressing an increase in maintenance costs are provided. can provide.

1 is a diagram showing a cell stack included in a fuel cell according to one embodiment; FIG. FIG. 2 illustrates an SOFC module according to one embodiment; 1 is a cross-sectional view of an SOFC cartridge according to one embodiment; FIG. FIG. 3 is a schematic diagram showing an example arrangement of a plurality of SOFC cartridges in the pressure vessel of FIG. 2; 1 is a block configuration diagram of a control device for a fuel cell according to one embodiment; FIG. 4 is a flowchart illustrating a temperature evaluation method according to one embodiment; FIG. 7 is a configuration diagram schematically showing the fuel cell cartridge selected in step S10 of FIG. 6 together with its peripheral configuration; It is an example of the characteristic map memorize|stored in the memory|storage part. FIG. 4 is a block configuration diagram of a control device for a fuel cell according to another embodiment; It is another example of the characteristic map memorize|stored in the memory|storage part. 6 is a flow chart showing a control method of the fuel cell module implemented by the controller of FIG. 5; It is an example of correction of the target value in step S25 of FIG. FIG. 11 is another correction example of the target value in step S25 of FIG. 10. FIG.

An embodiment of a fuel cell control device and control method according to the present invention will be described below with reference to the drawings.

In the following, for convenience of explanation, the positional relationship of each component described using the expressions "above" and "below" with respect to the paper plane indicates the vertically upper side and the vertically lower side, respectively. Further, in this embodiment, the same effect can be obtained in the vertical direction and the horizontal direction. good.

First, the configuration of the fuel cell, which is the evaluation target of the temperature evaluation device, will be described. In the following description, a solid oxide fuel cell (SOFC) is described as an example of a fuel cell. Further, although a cylindrical (cylindrical) cell stack 101 of a solid oxide fuel cell (SOFC) is described as an example, it is not necessarily limited to this, and for example, a flat cell stack may be used. Although the fuel cell is formed on the substrate, the electrode (fuel electrode or air electrode) may be thickly formed instead of the substrate to serve as the substrate.

FIG. 1 is a diagram showing a cell stack 101 included in a fuel cell according to one embodiment. FIG. 1 shows a cylindrical cell stack using substrate tubes as an example of the cell stack 101 . When the substrate tube is not used, for example, the fuel electrode may be formed thick and used as the substrate tube, and the use of the substrate tube is not limited. Further, although the substrate tube in this embodiment is described as having a cylindrical shape, the substrate tube may be cylindrical, and the cross section is not necessarily limited to a circular shape, and may be an elliptical shape, for example. A cell stack such as a flat tubular in which the peripheral surface of the cylinder is vertically crushed may be used.

The cell stack 101 includes, for example, a cylindrical base tube 103, a plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103, and an interconnector 107 formed between adjacent fuel cells 105. . The fuel cell 105 is formed by laminating a fuel electrode 109, a solid electrolyte membrane 111, and an air electrode 113. As shown in FIG. In addition, the cell stack 101 is attached to the air electrode 113 of the fuel cell 105 formed at one end of the base tube 103, which is the most end in the axial direction of the base tube 103, among the plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103. , a lead film 115 electrically connected via an interconnector 107, and a lead film 115 electrically connected to the fuel electrode 109 of the fuel cell 105 formed at the other end of the most end.

The substrate tube 103 is made of a porous material, such as CaO _- stabilized ZrO2 ₍ CSZ), a mixture of CSZ and nickel oxide (NiO) (CSZ+NiO), or Y2O3 _- stabilized ZrO2 ₍ YSZ), or The main component is MgAl ₂ O ₄ or the like. The substrate tube 103 supports the fuel cell 105, the interconnector 107, and the lead film 115, and also allows the fuel gas supplied to the inner peripheral surface of the substrate tube 103 to pass through the substrate tube 103 through the pores of the substrate tube 103. is diffused to the fuel electrode 109 formed on the outer peripheral surface of the .

The fuel electrode 109 is composed of a composite oxide of Ni and a zirconia-based electrolyte material, such as Ni/YSZ. The thickness of the fuel electrode 109 is 50 μm to 250 μm, and the fuel electrode 109 may be formed by screen printing slurry. In this case, the fuel electrode 109 has Ni, which is a component of the fuel electrode 109, catalyzing the fuel gas. This catalytic action causes the fuel gas supplied through the substrate tube 103, such as a mixed gas of methane (CH ₄ ) and water vapor, to react and reform into hydrogen (H ₂ ) and carbon monoxide (CO). It is. In addition, the fuel electrode 109 combines hydrogen (H ₂ ) and carbon monoxide (CO) obtained by reforming and oxygen ions (O ²⁻ ) supplied through the solid electrolyte membrane 111 with the solid electrolyte membrane 111. are electrochemically reacted near the interface to produce water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell 105 generates electricity by electrons released from the oxygen ions.

Fuel gases that can be supplied to and used by the fuel electrode 109 include hydrocarbon gases such as hydrogen (H ₂ ), ammonia (NH ₃ ), carbon monoxide (CO), and methane (CH ₄ ), city gas, and natural gas. Other examples include gasification gas produced by gasification equipment from carbon-containing raw materials such as petroleum, methanol, and coal.

The solid electrolyte membrane 111 is mainly made of YSZ, which has airtightness and high oxygen ion conductivity at high temperatures. This solid electrolyte membrane 111 moves oxygen ions (O ²⁻ ) generated at the air electrode to the fuel electrode. The thickness of the solid electrolyte membrane 111 located on the surface of the fuel electrode 109 is 10 μm to 100 μm, and the solid electrolyte membrane 111 may be formed by screen printing slurry.

The air electrode 113 is made of, for example, LaSrMnO ₃ -based oxide or LaCoO ₃ -based oxide, and slurry is applied to the air electrode 113 by screen printing or using a dispenser. This air electrode 113 generates oxygen ions (O ²⁻ ) by dissociating oxygen in an oxidizing gas such as supplied air near the interface with the solid electrolyte membrane 111 .

The air electrode 113 can also have a two-layer structure. In this case, the air electrode layer (intermediate air electrode layer) on the solid electrolyte membrane 111 side exhibits high ion conductivity and is composed of a material with excellent catalytic activity. The cathode layer (cathode conductive layer) on the cathode intermediate layer may be composed of a perovskite oxide represented by Sr- and Ca-doped LaMnO ₃ . By doing so, power generation performance can be further improved.

The oxidizing gas is a gas containing approximately 15% to 30% oxygen, and air is typically suitable. is available.

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, L is a lanthanide element) such as SrTiO ₃ system, and the slurry is screen-printed. do. The interconnector 107 is a dense film that prevents mixing of the fuel gas and the oxidizing gas. In addition, the interconnector 107 has stable durability and electrical conductivity in both an oxidizing atmosphere and a reducing atmosphere. This interconnector 107 electrically connects the air electrode 113 of one fuel cell 105 and the fuel electrode 109 of the other fuel cell 105 in the adjacent fuel cells 105, and connects the adjacent fuel cells 105 to each other. are connected in series.

The lead film 115 is required to have electronic conductivity and to have a coefficient of thermal expansion close to that of other materials constituting the cell stack 101. Therefore, the combination of Ni such as Ni/YSZ and the zirconia-based electrolyte material is preferable. It is composed of M1-xLxTiO ₃ (M is an alkaline earth metal element, L is a lanthanide element) such as a composite material or SrTiO ₃ system. This lead film 115 guides the DC power generated by the plurality of fuel cells 105 connected in series by the interconnector 107 to near the end of the cell stack 101 .

Next, an SOFC module 201 (fuel cell module) and an SOFC cartridge 203 (fuel cell cartridge) according to one embodiment will be described with reference to FIGS. 2 and 3. FIG. Here, FIG. 2 is a diagram showing an SOFC module 201 according to one embodiment, and FIG. 3 is a cross-sectional diagram showing an SOFC cartridge 203 according to one embodiment.

The SOFC module 201 includes, for example, a plurality of SOFC cartridges 203 and a pressure vessel 205 that houses the plurality of SOFC cartridges 203, as shown in FIG. Although the cylindrical SOFC cell stack 101 is illustrated in FIG. 2, it is not necessarily limited to this, and for example, a flat cell stack may be used. The SOFC module 201 also 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. The SOFC module 201 also includes an oxidizing gas supply pipe (not shown), a plurality of oxidizing gas supply branch pipes (see FIG. 7), an oxidizing gas discharge pipe (not shown) and a plurality of oxidizing gas discharge branch pipes. (See FIG. 7).

The fuel gas supply pipe 207 is provided outside the pressure vessel 205 and is connected to a fuel gas supply unit that supplies fuel gas with a predetermined gas composition and a predetermined flow rate corresponding to the power generation amount of the SOFC module 201. It is connected to the fuel gas supply branch pipe 207a. The fuel gas supply pipe 207 branches and guides a predetermined flow rate of the fuel gas supplied from the fuel gas supply section described above to a plurality of fuel gas supply branch pipes 207a. Further, the fuel gas supply branch pipe 207 a is connected to the fuel gas supply pipe 207 and also to the plurality of SOFC cartridges 203 . The fuel gas supply branch pipe 207a guides the fuel gas supplied from the fuel gas supply pipe 207 to the plurality of SOFC cartridges 203 at a substantially uniform flow rate, thereby substantially uniforming the power generation performance of the plurality of SOFC cartridges 203. .

The fuel gas discharge branch pipe 209 a is connected to the plurality of SOFC cartridges 203 and to the fuel gas discharge pipe 209 . This fuel gas discharge branch pipe 209 a guides the exhaust fuel gas 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 209 a and part of it is arranged outside the pressure vessel 205 . This fuel gas discharge pipe 209 guides the exhaust fuel gas discharged from the fuel gas discharge branch pipe 209 a at a substantially uniform 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 3 MPa and an internal temperature of from the atmospheric temperature to about 550° C., it has durability and corrosion resistance to oxidants such as oxygen contained in the oxidizing gas. The materials we have are used. For example, a stainless steel material such as SUS304 is suitable.

Here, in this embodiment, a plurality of SOFC cartridges 203 are grouped and housed in the pressure vessel 205 . FIG. 4 is a schematic diagram showing an arrangement example of a plurality of SOFC cartridges 203 inside the pressure vessel 205 of FIG. The arrangement layout and number of the plurality of SOFC cartridges 203 in the pressure vessel 205 may be arbitrary, but in this embodiment, the plurality of SOFC cartridges 203 are arranged adjacent to each other.

FIG. 4 shows a case where four SOFC cartridges 203A, 203B, 203C, and 203D are arranged in order along one direction as one layout example inside the pressure vessel 205. As shown in FIG. One side of the leftmost SOFC cartridge 203A is exposed to the outside (atmosphere in the pressure vessel 205 or the inner wall surface of the pressure vessel 205), and the adjacent SOFC cartridge 203B is disposed on the other side. SOFC cartridge 203B has SOFC cartridges 203A and 203C adjacent to each other on both sides thereof. The SOFC cartridge 203C is flanked by SOFC cartridges 203B and 203D on both sides thereof. The SOFC cartridge 203D is arranged adjacent to the SOFC cartridge 203C on one side, and the other side is exposed to the outside (the atmosphere inside the pressure vessel 205 or the inner wall surface of the pressure vessel 205).

The SOFC cartridge 203, as shown in FIG. 223. The SOFC cartridge 203 also includes an upper tube sheet 225a, a lower tube sheet 225b, an upper heat insulator 227a, and a lower heat insulator 227b. In the present embodiment, the SOFC cartridge 203 has the fuel gas supply header 217, the fuel gas discharge header 219, the oxidizing gas supply header 221, and the oxidizing gas discharge header 223 arranged as shown in FIG. , the fuel gas and the oxidizing gas flow inside and outside the cell stack 101 facing each other. Alternatively, the oxidizing gas may flow in a direction perpendicular to the longitudinal direction of the cell stack 101 .

The power generation chamber 215 is a region formed between the upper heat insulator 227a and the lower heat insulator 227b. The power generation chamber 215 is a region in which the fuel cells 105 of the cell stack 101 are arranged, and is a region in which the fuel gas and the oxidizing gas are electrochemically reacted to generate power. Further, the temperature near the central portion of the cell stack 101 in the longitudinal direction of the power generation chamber 215 is monitored by being evaluated by a temperature evaluation device to be described later. becomes a high-temperature atmosphere.

The fuel gas supply header 217 is an area surrounded by the upper casing 229a and the upper tube plate 225a of the SOFC cartridge 203. The fuel gas supply branch pipe 207a is connected to the fuel gas supply branch pipe 207a 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 tube plate 225a and the sealing member 237a. is introduced into the substrate tubes 103 of the plurality of cell stacks 101 at a substantially uniform flow rate to substantially uniform the power generation performance of the plurality of cell stacks 101 .

The fuel gas discharge header 219 is an area surrounded by the lower casing 229b and the lower tube plate 225b of the SOFC cartridge 203. The fuel gas discharge branch pipe 209a (not shown) is opened by the fuel gas discharge hole 231b provided in the lower casing 229b. is communicated with. In addition, the plurality of cell stacks 101 are joined to the lower tube plate 225b and the sealing member 237b, and the fuel gas discharge header 219 passes through the inside of the base tube 103 of the plurality of cell stacks 101 to the fuel gas discharge header 219. The exhaust fuel gas supplied to is collected and led to the fuel gas discharge branch pipe 209a through the fuel gas discharge hole 231b.

An oxidizing gas having a predetermined gas composition and a predetermined flow rate corresponding to the amount of power generated by the SOFC module 201 is branched to an oxidizing gas supply branch pipe (not shown) and supplied to a plurality of SOFC cartridges 203 . The oxidizing gas supply header 221 is an area surrounded by the lower casing 229b, the lower tube sheet 225b, and the lower heat insulator 227b of the SOFC cartridge 203, and is supplied by the oxidizing gas supply holes 233a provided on the side surface of the lower casing 229b. , is communicated with an oxidizing gas supply branch pipe (not shown). The oxidizing gas supply header 221 receives a predetermined flow rate of oxidizing gas supplied from an oxidizing gas supply branch pipe (not shown) through an oxidizing gas supply hole 233a to generate power through an oxidizing gas supply gap 235a, which will be described later. It leads to chamber 215 .

The oxidizing gas discharge header 223 is an area surrounded by the upper casing 229a, the upper tube plate 225a, and the upper heat insulator 227a of the SOFC cartridge 203, and is discharged by the oxidizing gas discharge holes 233b provided on the side surface of the upper casing 229a. , is communicated with an oxidizing gas discharge branch pipe (not shown). The oxidizing gas discharge header 223 is shown through an oxidizing gas discharge hole 233b, which is supplied from the power generation chamber 215 to the fuel gas discharge header 223 through an oxidizing gas discharge gap 235b, which will be described later. It leads to an oxidizing gas discharge branch pipe that does not.

The upper tube sheet 225a is positioned between the top plate of the upper casing 229a and the upper heat insulator 227a so that the upper tube sheet 225a, the top plate of the upper casing 229a, and the upper heat insulator 227a are substantially parallel to each other. is fixed to the side plate of the 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. The upper tube plate 225a airtightly supports one end of each of the plurality of cell stacks 101 via one or both of a sealing member 237a and an adhesive member, and also includes a fuel gas supply header 217 and an oxidizing gas discharge header. 223.

The upper heat insulator 227a is arranged at the lower end of the upper casing 229a so that the upper heat insulator 227a, the top plate of the upper casing 229a, and the upper tube plate 225a are substantially parallel, and are fixed to the side plates of the upper casing 229a. there is Also, the upper heat insulator 227 a 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 larger than the outer diameter of the cell stack 101 . The upper heat insulator 227a has an oxidizing gas discharge gap 235b formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the upper heat insulator 227a.

The upper heat insulator 227a partitions the power generation chamber 215 and the oxidizing gas discharge header 223. When the atmosphere around the upper tube sheet 225a becomes hot, its strength decreases and corrosion due to the oxidizing agent contained in the oxidizing gas occurs. suppress the increase. Although the upper tube sheet 225a and the like are made of a metal material such as a nickel-based alloy that is resistant to high temperatures, the upper tube sheet 225a and the like are exposed to the high temperature inside the power generation chamber 215, and the temperature difference within the upper tube sheet 225a and the like increases. This prevents thermal deformation. The upper heat insulator 227a guides the exhaust oxidizing gas, which has passed through the power generation chamber 215 and is exposed to high temperatures, to the oxidizing gas exhaust header 223 through the oxidizing gas exhaust gap 235b.

According to this embodiment, due to the structure of the SOFC cartridge 203 described above, the fuel gas and the oxidizing gas flow inside and outside the cell stack 101 facing each other. As a result, the exhaust oxidizing gas undergoes heat exchange with the fuel gas supplied to the power generation chamber 215 through the interior of the substrate tube 103, and the upper tube sheet 225a made of a metal material is prevented from buckling. It is cooled to a temperature at which it does not deform and is supplied to the oxidizing gas discharge header 223 . Further, the temperature of the fuel gas is raised by heat exchange with the exhaust oxidizing gas discharged from the power generation chamber 215 and supplied to the power generation chamber 215 . As a result, the fuel gas 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 tube sheet 225b is placed between the bottom plate of the lower casing 229b and the lower heat insulator 227b, and on the side plate of the lower casing 229b so that the bottom plate of the lower tube sheet 225b, the bottom plate of the lower casing 229b, and the lower heat insulator 227b are substantially parallel to each other. Fixed. 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. The lower tube sheet 225b airtightly supports the other ends of the plurality of cell stacks 101 via one or both of the sealing member 237b and the adhesive member, and also includes the fuel gas discharge header 219 and the oxidizing gas supply header. 221.

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

The lower heat insulator 227b partitions the power generation chamber 215 and the oxidizing gas supply header 221. When the atmosphere around the lower tube sheet 225b becomes hot, its strength decreases and corrosion due to the oxidizing agent contained in the oxidizing gas occurs. suppress the increase. The lower tube sheet 225b and the like are made of a metal material with high temperature durability such as a nickel-based alloy, but the lower tube sheet 225b and the like are exposed to high temperatures and the temperature difference within the lower tube sheet 225b and the like increases, causing thermal deformation. This is to prevent The lower heat insulator 227b guides the oxidizing gas supplied to the oxidizing gas supply header 221 to the power generation chamber 215 through the oxidizing gas supply gap 235a.

According to this embodiment, due to the structure of the SOFC cartridge 203 described above, the fuel gas and the oxidizing gas flow inside and outside the cell stack 101 facing each other. As a result, the exhaust fuel gas that has passed through the interior of the substrate tube 103 and the power generation chamber 215 is heat-exchanged with the oxidizing gas supplied to the power generation chamber 215, and the lower tube plate 225b made of a metal material is produced. etc. are cooled to a temperature at which they are not deformed such as buckling and supplied to the fuel gas discharge header 219 . Also, the oxidizing gas is heated by heat exchange with the exhaust fuel gas and supplied to the power generation chamber 215 . As a result, the oxidizing gas heated to a 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 the lead films 115 made of Ni/YSZ or the like provided in the plurality of fuel cells 105, and then is supplied to the current collecting member of the SOFC cartridge 203 ( (not shown) via a current collecting plate (not shown) and taken out of each SOFC cartridge 203 . The DC power led to the outside of the SOFC cartridges 203 by the current collecting member is connected to the power generated by each SOFC cartridge 203 in a predetermined series number and parallel number, and is led out to the outside of the SOFC module 201. , is converted into predetermined AC power by a power conversion device (such as an inverter) such as a power conditioner (not shown), and supplied to a power supply destination (for example, a load facility or a power system).

The fuel cell module 201 having the above configuration includes a control device 300 as a control unit. The control device 300 includes, 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. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example, and the CPU reads out this program to a RAM or the like, and executes information processing and arithmetic processing. As a result, various functions are realized. The program is pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via 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.

FIG. 5 is a block configuration diagram of a control device 300 for a fuel cell (fuel cell module 201) according to one embodiment. The control device 300 includes a temperature evaluation device 302 and a control section 304 . The temperature evaluation device 302 is a configuration for evaluating the temperature of the power generation chamber 215 (hereinafter referred to as “power generation chamber temperature T” as appropriate) in the fuel cell cartridge 203 provided in the fuel cell module 201, and is an internal heat generation amount difference calculation unit. 306 , a storage unit 308 , and a generator chamber temperature calculation unit 310 . The controller 304 is configured to control the fuel cell module 201 based on the power generation chamber temperature T evaluated by the temperature evaluation device 302 .

The temperature evaluation device 302 evaluates the generator chamber temperature T in at least one of the plurality of fuel cell cartridges 203 included in the fuel cell module 201 . In other words, the temperature evaluation device 302 may evaluate the generating chamber temperature T for a portion selected from the plurality of fuel cell cartridges 203, or may evaluate the generating chamber temperature T for each of the plurality of fuel cell cartridges 203. may be evaluated.

In this embodiment, in order to explain the function of the temperature evaluation device 302 in an easy-to-understand manner, the case of evaluating the power generation chamber temperature T for one fuel cell cartridge 203 selected from a plurality of fuel cell cartridges 203 will be described. In this case, the fuel cell cartridge 203 to be evaluated may be selected based on the arrangement layout of the plurality of fuel cell cartridges 203, as described later.

The internal calorific value difference calculation unit 306 calculates the difference ΔQ between the initial state of the internal calorific value in the fuel cell cartridge 203 to be evaluated and the calorific value at the time of temperature estimation (hereinafter referred to as “internal calorific value difference ΔQ” as appropriate). It is a configuration for calculating. The calculation of the difference ΔQ in the amount of internal heat generation is performed, for example, by determining the heat balance in the fuel cell cartridge 203 . The heat balance is obtained based on the balance between the amount of heat input and the amount of exhaust heat, including the amount of heat generated in the initial state of the cartridge, which is known for the fuel cell cartridge 203, and the difference between the amount of heat input and the amount of exhaust heat, which is not measured. This is the external heat radiation loss Qloss from the fuel cell.

The storage unit 308 is configured to store a characteristic map M indicating the correlation between the difference ΔQ between the internal heat generation amount Q0 in the initial state and the internal heat generation amount Q at the time of temperature estimation, and the temperature T of the generator chamber. There is a correlation between the internal heat generation amount difference ΔQ and the generating chamber temperature T, and a characteristic map M is defined in advance by experimental, test, or simulation methods. As the tendency of the characteristic map M, the larger the difference ΔQ in the amount of internal heat generation, the greater the amount of heat discharged from the fuel cell cartridge 203 (the temperature rises), and the higher the temperature of the generator chamber. By performing a three-dimensional temperature simulation that simulates the power generation characteristics of the fuel cell cartridge 203 and the operating conditions of the fuel cell cartridge 203, the temperature distribution in the power generation chamber 215 can be predicted in more detail, and the positions where the maximum and minimum temperatures occur can be grasped. becomes possible. Such a characteristic map M is stored in advance in the storage unit 308 and prepared according to each condition, so that it can be read as appropriate.

Generating chamber temperature calculation unit 310 is configured to calculate, based on characteristic map M, generating chamber temperature T corresponding to internal heat generation amount difference ΔQ. Since the characteristic map M indicates the correlation between the internal heat generation amount difference ΔQ and the generating chamber temperature T as described above, the generating chamber temperature calculation unit 310 accesses the storage unit 308 and acquires the internal temperature based on the characteristic map M. A generator chamber temperature T corresponding to the difference ΔQ in the internal calorific value calculated by the calorific value difference calculator 306 is calculated. Instead of the internal heat generation difference ΔQ, a characteristic map for calculating the generating chamber temperature T from the internal heat generation amount Q obtained by adding the internal heat generation amount difference ΔQ to the initially set internal heat generation amount Q0 may be used.

The control unit 304 acquires the power generation chamber temperature T evaluated by the temperature evaluation device 302 in this way, and controls the fuel cell module 201 based on the power generation chamber temperature T. FIG. The generator chamber temperature T evaluated by the temperature evaluation device 302 can be displayed on a display unit such as a display in addition to or instead of being used by the control unit 304 to control the fuel cell module 201. It may be used for various operations of the fuel cell module 201 by grasping by a person.

Next, the temperature evaluation method performed by the temperature evaluation device 302 having the above configuration will be described more specifically. FIG. 6 is a flow chart showing a temperature evaluation method according to one embodiment.

First, the temperature evaluation device 302 selects at least one fuel cell cartridge 203 to be evaluated for the generating chamber temperature T from the plurality of fuel cell cartridges 203 included in the fuel cell module 201 (step S10). Here, in order to explain the function of the temperature evaluation device 302 in an easy-to-understand manner, the case of evaluating the generating chamber temperature T for one fuel cell cartridge 203 selected from a plurality of fuel cell cartridges 203 will be described. In this case, the fuel cell cartridge 203 to be evaluated may be selected based on the arrangement layout of the plurality of fuel cell cartridges 203, as described later.

For example, as described above with reference to FIG. 4, in a layout in which a plurality of fuel cell cartridges 203A, 203B, 203C, and 203D are adjacent to each other along one direction, the inner fuel cell cartridges 203B and 203C are Since heat radiation is disadvantageous compared to the fuel cell cartridges 203A and 203D arranged on the outer side, the temperature tends to be high. Useful in monitoring for exceeding the upper limit of a range. On the other hand, the fuel cell cartridges 203A and 203D arranged outside are more advantageous in terms of heat dissipation than the fuel cell cartridges 203B and 203C arranged inside, and tend to be at low temperatures. is useful when monitoring that the generator chamber temperature T falls below the lower limit of the allowable range.

Here, FIG. 7 is a schematic diagram showing the configuration of the fuel cell cartridge 203 selected in step S10 of FIG. 6 together with its peripheral configuration. In FIG. 7, a fuel gas supply branch pipe 207a for supplying fuel gas to the fuel cell cartridge 203 to be evaluated, a fuel gas discharge branch pipe 209a for discharging fuel gas from the fuel cell cartridge 203, An oxidizing gas supply branch 207b for supplying oxidizing gas to the fuel cell cartridge 203 and an oxidizing gas discharge branch 209b for discharging the oxidizing gas from the fuel cell cartridge 203 are shown. .

The fuel cell cartridge 203 is supplied with a fuel gas having a temperature T _F1 and a flow rate F _F through a fuel gas supply branch pipe 207a, and is supplied with a temperature T _A1 and a flow rate A _F through an oxidizing gas supply branch pipe 207b. An oxidizing gas is supplied. From the fuel cell cartridge 203, the fuel gas at temperature T _F2 is discharged through the fuel gas discharge branch pipe 209a, and the oxidizing gas at temperature T _A2 is discharged through the oxidizing gas discharge branch pipe 209b. .

The fuel cell cartridge 203 also has an output circuit 320 for leading DC power to the outside by the current collecting member. The DC power derived from the output circuit 320 has an output current A and an output voltage V. FIG.

These temperatures T _F1 , T _F2 , T _A1 , T _A2 , flow rates F _F , A _F , output current A, and output voltage V can be detected by corresponding sensors, and the temperature evaluation device 302 can detect these sensor detection values can be acquired.

Subsequently, the temperature evaluation device 302 acquires an output command for the fuel cell module 201 (step S11), and based on the output command, the target value of the output current A (output current target value) in the fuel cell cartridge 203 selected in step S10. value) is set (step S12). In the fuel cell cartridge 203, characteristics regarding the output current A and the output voltage V (so-called IV characteristics) are defined as initial values or planned values, and in step S12, based on the characteristics obtained in step S11. An output current target value corresponding to the output command is set.

Subsequently, the temperature evaluation device 302 determines the target values of the flow rate F _F of the fuel gas and the flow rate A _F of the oxidizing gas supplied to the fuel cell cartridge 203 based on the output current target value set in step S12. Set (step S13). That is, in step S13, in order to make the output current A of the fuel cell cartridge 203 equal to the output current target value set in step S12, the flow rate of the fuel gas to be supplied to the fuel cell cartridge ₂₀₃ and the amount of oxidizing gas are A target value for the flow rate _AF is determined respectively. Calculation of the target values for the fuel gas flow rate F _F and the oxidizing gas flow rate A _F is performed using the fuel utilization rate Uf and the air utilization rate Ua that are predetermined for the fuel cell cartridge 203 .

Subsequently, the internal calorific value difference calculator 306 calculates the internal calorific value difference ΔQ based on the heat balance in the fuel cell cartridge 203 (step S14). The calculation of the internal heat generation amount difference ΔQ in step S 14 is performed based on the heat balance in the fuel cell cartridge 203 . The heat balance is obtained based on the balance between the amount of heat input and the amount of exhaust heat with respect to the fuel cell cartridge 203. As the difference between the initial internal heat generation amount Q0 and the internal heat generation amount Q at the time of temperature estimation, the difference ΔQ in the internal heat generation amount is Calculated.

The calculation of the difference ΔQ from the initial internal calorific value in step S14 is performed by combining the initial internal calorific value Q0 in the fuel cell cartridge 203 and the internal calorific value Q obtained from the heat mass balance in the fuel cell cartridge 203 at the time of temperature estimation. using the following formula:
ΔQ=Q-Q0 (1)

The internal calorific value Q is determined by the target values of the fuel gas flow rate _FF and the oxidizing gas flow rate _AF set in step S13, and the fuel gas inlet detected by various sensors provided in the fuel cell cartridge 203. Side temperature T _F1 (supply temperature) and outlet side temperature T _F2 (discharge temperature), inlet side temperature T _A1 (supply temperature) and outlet side temperature T _A2 (discharge temperature) of the oxidizing gas discharged from the fuel cell cartridge 203 calculated by evaluating the heat balance based on The initial internal heat generation amount Q0, which is used as a reference for estimating the temperature of the power generation chamber, is calculated as the heat generation amount associated with power generation in the fuel cell cartridge 203 based on the initial IV characteristics of the cartridge.

In the calculation of the heat balance for calculating the calorific value Q in this embodiment, the discharge flow rate of the fuel gas and the oxidizing gas in the fuel cell cartridge 203 is calculated from the current and the set fuel utilization rate Uf and air utilization rate Ua. A calculated flow rate may be used.

Subsequently, the generator chamber temperature calculator 310 calculates the generator chamber temperature T based on the internal heat generation amount difference ΔQ calculated in step S14 (step S15). The correlation between the internal heat generation amount difference ΔQ and the generating chamber temperature T is stored in advance as the characteristic map M stored in the storage unit 308 as described above, and the generating chamber temperature calculation unit 310 calculates the following based on the characteristic map M: A generator chamber temperature T corresponding to the internal heat generation amount difference ΔQ calculated in step S14 is obtained.

FIG. 8 is an example of the characteristic map M stored in the storage unit 308. As shown in FIG. As described above, the characteristic map M defines the correlation between the internal heat generation difference ΔQ and the generating chamber temperature T, and tends to increase the generating chamber temperature T as the internal heat generation difference ΔQ increases. FIG. 8 shows, as an example, the case where the internal heat generation amount difference ΔQ and the generator chamber temperature T are in a proportional relationship.

Such characteristic map M may be prepared for each type of fuel gas supplied to fuel cell cartridge 203 . This is because the internal calorific value Q generally varies depending on the type of fuel gas. For example, when city gas is used as fuel gas, heat is absorbed in the power generation reaction, but when hydrogen gas is used as fuel gas, heat is not absorbed in the power generation reaction. Therefore, the type of fuel gas affects the power generation chamber temperature T. receive.

Thus, the temperature evaluation device 302 can suitably evaluate the generator chamber temperature T without arranging a temperature sensor such as a thermocouple in the generator chamber 215 . Therefore, maintenance such as replacement work of the temperature sensor is not required, and the generator chamber temperature T can be monitored over a long period of time.

Here, FIG. 9A is a block configuration diagram of a control device 300' for a fuel cell (fuel cell module 201) according to another embodiment. The control device 300′ differs from the control device 300 (see FIG. 5) described above in that the temperature evaluation device 302 includes a temperature detection unit 307 instead of the internal heat generation amount difference calculation unit 306. FIG.

An example for estimating the generator chamber temperature more simply will now be described.
The temperature detection unit 307 is configured to detect the temperature T _F2 of the exhaust fuel gas of the fuel cell cartridge 203 and the temperature T _A2 of the exhaust oxidizing gas. In the controller 300', the correlation between the exhaust fuel gas temperature _TF2 and the exhaust oxidizing gas temperature _TA2 , and the generator chamber temperature T is stored as a characteristic map M in the storage unit 308. Then, when the fuel cell module 201 is in a substantially constant operating state, the power generation chamber temperature calculation unit 310 calculates the power generation corresponding to the detection result of the temperature detection unit 307 based on the characteristic map M stored in the storage unit 308. Room temperature T is calculated.

FIG. 9B is another example of the characteristic map M stored in the storage unit 308. FIG. The characteristic map M defines the correlation between the temperature T _F2 of the exhaust fuel gas and the temperature T _A2 of the exhaust oxidizing gas and the temperature T of the generator chamber, as described above. Multiple characteristic maps are set and stored for each condition that has a large effect on the temperature of the generator chamber, such as power output and supply air flow rate. It becomes possible to estimate the generator chamber temperature.

In this way, in the control device 300', when the fuel cell module 201 is in a substantially constant operating state, if there is no extreme change in the state of the fuel cell cartridge 203 (for example, a large amount of fuel leaks inside the cartridge), the heat balance is maintained. is stable, based on the temperature T _F2 of the fuel gas discharged from the fuel cell cartridge 203 and the temperature T _A2 of the oxidizing gas, which are highly correlated with the temperature of the power generation chamber, the temperature of the power generation chamber can be simply calculated as follows: T can be evaluated.

The control unit 304 is configured to control the fuel cell module 201 based on the power generation chamber temperature T evaluated as described above. Specifically, the control unit 304 adjusts at least one control parameter of the fuel cell module 201 so that the power generation chamber temperature T obtained from the temperature evaluation device 302 falls within a preset allowable range.

FIG. 10 is a flow chart showing a control method for the fuel cell module 201 implemented by the controller 304 of FIG.

First, the control unit 304 acquires the generator chamber temperature T, which is the evaluation result, from the temperature evaluation device 302 (step S20). Subsequently, the control unit 304 acquires the allowable range TR of the generator chamber temperature T (step S21). The allowable range TR of the generator chamber temperature T is set in advance as a temperature range specified by the upper limit temperature TH and the lower limit temperature TL appropriate for the fuel cell cartridge 203, as shown in FIG.

Note that the allowable range TR of the generator chamber temperature T may include a margin corresponding to a predetermined error. For example, since the plurality of fuel cell cartridges 203 constituting the fuel cell module 201 have not a little individual difference, the allowable range TR may be set in consideration of the individual difference.

Subsequently, the control unit 304 calculates the target value of the control parameter based on the output command to the fuel cell module 201 (step S22). is compared to determine whether or not the generator chamber temperature T is within the allowable range TR (step S23). As a result, if the generator chamber temperature T is within the allowable range TR (step S23: YES), the fuel cell module 201 is controlled by adjusting the control parameters so as to achieve the target value calculated in step S22. (step S24).

On the other hand, if the generator chamber temperature T is not within the allowable range TR (step S23: NO), the control unit 304 corrects the target value of the control parameter based on the output command to the fuel cell module 201 calculated in step S22 (step S25), the fuel cell module 201 is controlled by adjusting the control parameters so as to achieve the corrected target values (step S24). As a result, the fuel cell module 201 is controlled such that the power generation chamber temperature T is within the allowable range TR.

For example, as shown as case 1 in FIG. 11, when the generator chamber temperature T1 (corresponding to the internal heat generation amount difference ΔQ1) evaluated by the temperature evaluation device 302 exceeds the upper limit temperature TH of the allowable range TR, the control unit 304 identifies the internal heat generation amount difference ΔQ2 at which the generator chamber temperature T becomes equal to or lower than the upper limit temperature TH based on the characteristic map M, and corrects the target value of the control parameter so that the internal heat generation amount difference ΔQ2 is realized. do. As a result, as shown in case 2, the fuel cell module 201 is controlled so that the power generation chamber temperature T is within the allowable range TR.

Also, for example, as shown as case 3 in FIG. Based on the characteristic map M, the unit 304 identifies the internal heat generation amount difference ΔQ4 at which the generator chamber temperature T is equal to or higher than the lower limit temperature TL, and corrects the target value of the control parameter so that the internal heat generation amount difference ΔQ4 is realized. do. As a result, as shown in case 4, the fuel cell module 201 is controlled such that the power generation chamber temperature T is within the allowable range TR.

As described above, according to the above-described embodiments, it is possible to provide a fuel cell temperature evaluation apparatus and a temperature evaluation method capable of continuously evaluating the temperature of the generation chamber of the fuel cell over a long period of time while suppressing an increase in maintenance costs. Moreover, the fuel cell can be preferably controlled using the power generation chamber temperature evaluated in this way.

In addition, it is possible to appropriately replace the components in the above-described embodiments with well-known components without departing from the scope of the present disclosure, and the above-described embodiments may be combined as appropriate.

The contents described in each of the above embodiments are understood as follows, for example.

(1) A temperature evaluation device for a fuel cell according to one aspect,
Internal calorific value for calculating the difference between the initial internal calorific value of the fuel cell (for example, the fuel cell cartridge 203 in the above embodiment) and the internal calorific value at the time of temperature estimation (for example, the internal calorific value difference ΔQ in the above embodiment) a difference calculation unit (for example, the internal calorific value difference calculation unit 306 in the above embodiment);
A storage unit for storing a characteristic map (for example, the characteristic map M in the above embodiment) showing the correlation between the difference in the internal heat generation amount and the power generation chamber temperature (for example, the power generation chamber temperature T in the above embodiment) of the fuel cell ( For example, the storage unit 308 of the above embodiment),
A generating chamber temperature calculating unit (for example, the above The power generation chamber temperature calculation unit 310 of the embodiment),
Prepare.

According to the aspect (1) above, it is possible to suitably evaluate the temperature of the generator chamber without arranging a temperature sensor such as a thermocouple in the generator chamber. Therefore, maintenance such as replacement work of temperature sensors is not required, and it is possible to monitor the generator chamber temperature over a long period of time.

(2) In another aspect, in the aspect of (1) above,
The internal calorific value difference calculation unit calculates the internal calorific value difference by obtaining a heat balance in the fuel cell.

According to the aspect (2) above, it is possible to suitably calculate the difference in the amount of internal heat generation based on the heat balance in the fuel cell.

(3) In another aspect, in the aspect of (2) above,
The heat balance includes the amount of fuel gas supplied to the fuel cell, the inlet-side temperature and outlet-side temperature of the fuel gas, the amount of oxidizing gas supplied to the fuel cell, the oxidizing inlet-side temperature and outlet-side temperature, It is calculated based on the amount of heat generated by the power generation in the fuel cell.

According to the aspect (3) above, the heat balance in the fuel cell can be suitably obtained by considering these factors.

(4) A fuel cell temperature evaluation device according to another aspect includes:
The temperature of the exhaust fuel gas from the fuel cell (for example, the fuel cell cartridge 203 in the above embodiment) (for example, the temperature T _F2 in the above embodiment) and the temperature of the exhaust oxidizing gas (for example, the temperature T _A2 in the above embodiment) are A temperature detection unit for detecting (for example, the temperature detection unit 307 in the above embodiment),
A characteristic indicating the correlation between the temperature of the exhaust fuel gas from the fuel cell, the temperature of the exhaust oxidizing gas from the fuel cell, and the temperature of the power generation chamber of the fuel cell (for example, the power generation chamber temperature T in the above embodiment) a storage unit (for example, the storage unit 308 in the above embodiment) for storing a map (for example, the characteristic map M in the above embodiment);
generating chamber temperature calculation for calculating the generating chamber temperature corresponding to the detection result of the temperature detecting unit based on the characteristic map stored in the storage unit when the fuel cell is in a substantially constant operating state; section (for example, the power generation chamber temperature calculation section 310 in the above embodiment);
Prepare.

According to the aspect (4) above, when the operating state of the fuel cell is substantially constant, the generator chamber temperature is simply calculated based on the temperatures of the fuel gas and the oxidizing gas discharged from the fuel cell. be able to.

(5) In another aspect, in any one aspect of (1) to (4) above,
said fuel cell comprising a plurality of fuel cell cartridges arranged adjacent to each other;
The generating chamber temperature calculating unit calculates the generating chamber temperature for a fuel cell cartridge farthest from an end of the plurality of fuel cell cartridges.

According to the aspect (5) above, when the fuel cell is configured by arranging a plurality of fuel cell cartridges adjacent to each other along one direction, the fuel cell cartridge farthest from the end portion A temperature is calculated. As a result, by determining the power generation chamber temperature of the fuel cell cartridge, which is difficult to dissipate heat and is most likely to increase in temperature, it is possible to appropriately monitor whether the temperature of the fuel cell exceeds the upper limit temperature.

(6) In another aspect, in any one aspect of (1) to (5) above,
The characteristic map is prepared for each type of fuel gas supplied to the fuel cell.

According to the aspect (6) above, a characteristic map is prepared for each type of fuel gas in accordance with changes in the internal calorific value depending on the type of fuel gas.

(7) A control device for a fuel cell according to one aspect (for example, the control devices 300 and 300' of the above embodiments)
a fuel cell temperature evaluation device according to any one of (1) to (6) above (for example, the temperature evaluation device 302 according to the above embodiment);
a control unit (for example, the control unit 304 in the above embodiment) for controlling the fuel cell based on the power generation chamber temperature calculated by the power generation chamber temperature calculation unit;
Prepare.

According to the aspect (7) above, the fuel cell can be preferably controlled based on the power generation chamber temperature evaluated by the temperature evaluation device.

(8) In another aspect, in the aspect of (7) above,
The controller controls the control parameters of the fuel cell so that the temperature of the generator chamber falls within an allowable range (for example, the allowable range TR in the above embodiment).

According to the aspect (8) above, the fuel cell can be suitably controlled using the power generation chamber temperature evaluated by the above-described temperature evaluation device so that the temperature of the power generation chamber is within the allowable range.

(9) In another aspect, in the aspect of (8) above,
The control unit controls the control parameter so that the temperature of the generator chamber is lower than the upper limit temperature of the allowable range.

According to the aspect (9) above, when the generator chamber temperature, which is the evaluation result, is higher than the upper limit temperature of the allowable range, the fuel cell module is controlled so that the generator chamber temperature is within the allowable range.

(10) In another aspect, in the above aspect (8) or (9),
The allowable range is defined including an error corresponding to individual differences among the plurality of fuel cell cartridges included in the fuel cell.

According to the above aspect (10), even if there are individual differences among the plurality of fuel cell cartridges that make up the fuel cell, each fuel cell can It becomes possible to control the fuel cell so that the temperature of the generation chamber of the cartridge is within the allowable range.

(11) A fuel cell temperature evaluation method according to one aspect includes:
a step of calculating a difference (for example, the internal heat value difference ΔQ in the above embodiment) between the initial internal heat value of the fuel cell (for example, the fuel cell cartridge 203 of the above embodiment) and the internal heat value at the time of temperature estimation;
Based on a characteristic map (for example, the characteristic map M in the above embodiment) showing the correlation between the difference in the internal heat generation amount and the temperature of the power generation chamber of the fuel cell (for example, the temperature of the power generation chamber T in the above embodiment), the internal heat generation amount a step of calculating the generating chamber temperature corresponding to the difference of
Prepare.

According to the aspect (11) above, it is possible to suitably evaluate the temperature of the generator chamber without arranging a temperature sensor such as a thermocouple in the generator chamber. Therefore, maintenance such as replacement work of temperature sensors is not required, and it is possible to monitor the generator chamber temperature over a long period of time.

101 Cell stack 103 Base tube 105 Fuel cell 107 Interconnector 109 Fuel electrode 111 Solid electrolyte membrane 113 Air electrode 115 Lead membrane 201 Fuel cell module 203 Fuel cell cartridge 205 Pressure vessel 207 Fuel gas supply pipe 207a Fuel gas supply branch pipe 207b Oxidation Chemical gas supply branch pipe 209 Fuel gas discharge pipe 209a Fuel gas discharge branch pipe 209b Oxidizing gas discharge branch pipe 215 Power generation chamber 217 Fuel gas supply header 219 Fuel gas discharge header 221 Oxidizing gas supply header 223 Oxidizing gas discharge header 225a Upper part Tube sheet 225b Lower tube sheet 227a Upper insulator 227b Lower insulator 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 Oxidation Gas discharge gaps 237a, 237b Seal member 300 Control device 302 Temperature evaluation device 304 Control unit 306 Internal calorific value difference calculation unit 307 Temperature detection unit 308 Storage unit 310 Power generation chamber temperature calculation unit 320 Output circuit

Claims (11)

an internal calorific value difference calculator for calculating the difference between the initial internal calorific value of the fuel cell and the internal calorific value at the time of temperature estimation;
a storage unit for storing a characteristic map indicating the correlation between the difference in the internal heat generation amount and the temperature of the generation chamber of the fuel cell;
a generator chamber temperature calculator for calculating the generator chamber temperature corresponding to the difference in the internal calorific value calculated by the internal calorific value difference calculator, based on the characteristic map stored in the storage unit;
A fuel cell temperature evaluation device comprising: 2. The temperature evaluation device for a fuel cell according to claim 1, wherein said internal heat generation amount difference calculating section calculates the difference in said internal heat generation amount by obtaining a heat balance in said fuel cell. The heat balance includes the amount of fuel gas supplied to the fuel cell, the inlet-side temperature and outlet-side temperature of the fuel gas, the amount of oxidizing gas supplied to the fuel cell, the oxidizing inlet-side temperature and outlet-side temperature, 3. The fuel cell temperature evaluation device according to claim 2, wherein the temperature is calculated based on the amount of heat generated by the power generation in the fuel cell. a temperature detection unit for detecting the temperature of the exhaust fuel gas from the fuel cell and the temperature of the exhaust oxidizing gas from the fuel cell;
a storage unit for storing a characteristic map indicating the correlation between the temperature of the exhaust fuel gas from the fuel cell, the temperature of the exhaust oxidizing gas from the fuel cell, and the temperature of the generation chamber of the fuel cell;
generating chamber temperature calculation for calculating the generating chamber temperature corresponding to the detection result of the temperature detecting unit based on the characteristic map stored in the storage unit when the fuel cell is in a substantially constant operating state; Department and
A fuel cell temperature evaluation device comprising: said fuel cell comprising a plurality of fuel cell cartridges arranged adjacent to each other;
5. The fuel cell according to any one of claims 1 to 4, wherein the power generation chamber temperature calculation unit calculates the power generation chamber temperature for a fuel cell cartridge farthest from an end of the plurality of fuel cell cartridges. Temperature evaluation device. 6. The fuel cell temperature evaluation device according to claim 1, wherein said characteristic map is prepared for each type of fuel gas supplied to said fuel cell. a fuel cell temperature evaluation device according to any one of claims 1 to 6;
a controller for controlling the fuel cell based on the generator chamber temperature calculated by the generator chamber temperature calculator;
A control device for a fuel cell, comprising: 8. The fuel cell control device according to claim 7, wherein said control unit controls control parameters of said fuel cell so that said generator chamber temperature is within an allowable range. 9. The fuel cell control device according to claim 8, wherein said control unit controls said control parameter so that said generator chamber temperature is lower than the upper limit temperature of said allowable range. 10. The fuel cell control device according to claim 8, wherein said allowable range is defined including an error corresponding to individual differences among a plurality of fuel cell cartridges provided in said fuel cell. a step of calculating a difference between an initial internal calorific value of the fuel cell and an internal calorific value at the time of temperature estimation;
calculating the temperature of the power generation chamber corresponding to the difference in the amount of internal heat generation based on a characteristic map showing the correlation between the difference in the amount of internal heat generation and the temperature of the generation chamber of the fuel cell;
A fuel cell temperature evaluation method comprising:

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