JP7503896B2 - Fuel Cell Device - Google Patents

Description

This disclosure relates to a fuel cell device.

Various fuel cell devices have been proposed, including a module that includes a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas, and a reformer that produces the fuel gas to be supplied to the fuel cell through reforming.

The power generation operation of the fuel cell device may be temporarily stopped in order to perform maintenance on the fuel cell device. The fuel cell device is restarted after the maintenance is completed. For example, Patent Document 1 discloses a fuel cell device that skips part of the normal startup operation sequence if the temperature of the module, reformer, etc. is equal to or higher than a predetermined temperature at the time of restart, thereby shortening the startup time at the time of restart.

JP 2013-191585 A

Conventional fuel cell devices can sometimes reduce the durability of the fuel cell device when restarted.

The fuel cell device of the present disclosure includes: a module including a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas;
a reformer that reforms a raw fuel to generate a fuel gas to be supplied to the fuel cell;
An auxiliary device for operating the fuel cell;
and a control device that controls the operation of the auxiliary devices. The control device controls at least some of the auxiliary devices not to operate when the power generation operation is stopped and the temperature of at least one of the module and the reformer is equal to or higher than a predetermined temperature.

The fuel cell device disclosed herein can prevent deterioration of the durability of the fuel cell device due to restarts, etc.

1 is a schematic diagram of a fuel cell device according to an embodiment; FIG. 2 is a perspective view showing the configuration of the fuel cell device inside the exterior case.

The following describes a fuel cell device according to an embodiment of the present disclosure with reference to the drawings.

Figure 1 is a schematic diagram of a fuel cell device according to an embodiment, and Figure 2 is a perspective view showing the configuration of the fuel cell device inside the exterior case.

The fuel cell device 100 of the embodiment includes a module 1 including a fuel cell 11 housed in a storage container 10. The fuel cell 11 may be any fuel cell that generates electricity using a fuel gas and an oxygen-containing gas. The fuel cell 11 may have, for example, a cell stack structure in which a plurality of fuel cell cells are arranged. The fuel cell 11 having a cell stack structure may be constructed, for example, by fixing the lower end of each fuel cell to a manifold using an insulating bonding material such as a glass sealant.

The fuel cell device 100 has a reformer 12 that generates fuel gas to be supplied to the fuel cell 11. The reformer 12 generates fuel gas by steam reforming raw fuel gas such as natural gas or LP gas. For example, as shown in FIG. 1, the reformer 12 is housed in a storage container 10, similar to the fuel cell 11.

The fuel cell device 100 has a first temperature measurement unit TC1 that measures the temperature of the module 1. A known measurement device such as a thermocouple can be used as the first temperature measurement unit TC1. In the embodiment, the temperature at the center position of the fuel cell 11 is measured by a thermocouple as the temperature of the module 1.

The fuel cell device 100 has a second temperature measurement unit TC2 that measures the temperature of the reformer 12. A known measurement device such as a thermocouple can be used as the second temperature measurement unit TC2. In the embodiment, the temperature at the inlet of the reformer 12 is measured by a thermocouple as the temperature of the reformer 12. The reformer 12 has an internal vaporization unit that generates water vapor, and a reforming unit that reacts the water vapor generated in the vaporization unit with the raw fuel gas to generate reformed gas. The inlet of the reformer 12 refers to the part of the vaporization unit that connects to the reforming unit.

The fuel cell device 100 includes a first heat exchanger 2 that exchanges heat between the exhaust gas (exhaust heat) from the module 1 and a heat medium, and a heat storage tank 3 that stores the heat medium. The heat storage tank 3 is provided with a water level sensor WL. The water level sensor WL is configured to detect the water level in the heat storage tank 3 when the water level is equal to or higher than a predetermined water level, and not to detect the water level when the water level in the heat storage tank 3 is below the predetermined water level. The predetermined water level may be, for example, a water level corresponding to a water amount that is 60 to 80% of the capacity of the heat storage tank 3. A known water level sensor such as a float sensor can be used as the water level sensor WL.

The fuel cell device 100 includes a first heat circulation system HC1 including a first heat exchanger 2, a heat storage tank 3, a heat medium pump P1, and piping connecting these. The fuel cell device 100 may include a second heat circulation system HC2 including a second heat exchanger 5, a heat pump P2 that circulates the heat medium from the heat storage tank 3, and piping connecting these. The fuel cell device 100 may be configured to use a high-temperature heat medium stored in the heat storage tank 3 to heat water such as tap water supplied from the outside through a supply flow path Kin in the second heat exchanger 5, and to supply the heated water through a supply flow path Kout to a reheating device such as an external water heater. The fuel cell device 100 may be a so-called monogeneration system that does not supply hot water to the outside.

The fuel cell device 100 includes an oxygen-containing gas supply device 14 having an oxygen-containing gas flow path F, a fuel gas supply device 15 having a fuel gas flow path G, and a reforming water supply device 16 having a reforming water flow path R. The oxygen-containing gas flow path F, the fuel gas flow path G, and the reforming water flow path R are provided with auxiliary equipment for operating the fuel cell device 100. The oxygen-containing gas flow path F is provided with auxiliary equipment such as an air flow meter FM2 and a blower B2. The fuel gas flow path G is provided with auxiliary equipment such as a first solenoid valve V1, a pressure sensor PS, a fuel pump B1, a gas flow meter FM1, and a second solenoid valve V2. The reforming water flow path R is provided with auxiliary equipment such as a water pump P3.

The oxygen-containing gas used to generate electricity in the fuel cell 11 is introduced into the fuel cell 11 by the oxygen-containing gas supply device 14. The raw fuel gas used to generate electricity in the fuel cell 11 is introduced into the reformer 12 by the fuel gas supply device 15.

The exhaust gas discharged from the module 1 exchanges heat with the heat medium flowing in the first heat exchanger 2 in the first heat exchanger 2. At this time, the moisture contained in the exhaust gas condenses to produce condensed water. The condensed water produced is collected via the condensed water flow path C and stored in the reforming water tank 6. The exhaust gas from which the moisture has been removed is exhausted outside the fuel cell device 100 via the exhaust gas flow path E. The condensed water stored in the reforming water tank 6 is supplied to the reformer 12 by the reforming water supply device 16 and used as reforming water.

The fuel cell device 100 further includes a power conditioner 20, a control device 30, and an operation board 40 including a display device and an operation panel as auxiliary devices that assist the power generation operation. The fuel cell device 100 is disposed in a case 50 consisting of frames 51 and exterior panels 52, for example, as shown in FIG. 2.

The control device 30 includes at least one processor, memory device, etc., and provides control and processing power to perform various functions, as described in detail below.

According to various embodiments, the at least one processor may be implemented as a single integrated circuit or as multiple communicatively coupled integrated circuits and/or discrete circuits. The at least one processor may be implemented according to various known techniques.

In one embodiment, a processor includes one or more circuits or units configured to perform one or more data computation procedures or processes, e.g., by executing instructions stored in associated memory. In other embodiments, a processor may be firmware, e.g., discrete logic components, configured to perform one or more data computation procedures or processes.

According to various embodiments, the processor may include one or more processors, controllers, microprocessors, microcontrollers, application specific integrated circuits, digital signal processors, programmable logic devices, field programmable gate arrays, or any combination of these devices or configurations, or other known combinations of devices and configurations, to perform the functions described below.

The control device 30 is connected to a storage device and a display device (both not shown) and to the various components and sensors that make up the fuel cell device 100, and controls and manages the entire fuel cell device 100, including each of these functional parts. The control device 30 obtains a program stored in an associated storage device and executes this program to realize various functions associated with each part of the fuel cell device 100.

When the control device 30 transmits control signals or various information to other functional units or devices, the control device 30 and the other functional units may be connected by wire or wirelessly. The control performed by the control device 30, which is characteristic of the embodiment, will be described later. In the embodiment, the control device 30 controls various auxiliary devices based on instructions and commands from external devices connected to the fuel cell device, and instructions and measurement values from the various sensors mentioned above. In the figures, the connection lines connecting the control device 30 to each device and each sensor that constitutes the fuel cell may be omitted.

The storage device (not shown) can store programs and data. The storage device may also be used as a working area for temporarily storing processing results. The storage device includes a recording medium. The recording medium may include any non-transitory storage medium, such as a semiconductor storage medium and a magnetic storage medium. The storage device may also include multiple types of storage media. The storage device may include a combination of a portable storage medium, such as a memory card, an optical disk, or a magneto-optical disk, and a storage reader. The storage device may include a storage device used as a temporary storage area, such as a RAM (Random Access Memory).

The control device 30 and the storage device of the fuel cell device can also be realized as a configuration that is external to the fuel cell device 100. Furthermore, it is also possible to realize it as a control method that includes the characteristic control steps of the control device 30 according to the present disclosure, or to realize it as a control program for causing a computer to execute the above steps.

The fuel cell device 100 is capable of operating a specific auxiliary device (also referred to as independent auxiliary operation) while the power generation operation (also referred to simply as operation) is stopped in order to inspect, replace, and perform other maintenance on the auxiliary devices. When the control device 30 receives an instruction (also referred to as an independent operation instruction) to operate a specific auxiliary device while the operation is stopped, it is capable of operating the specific auxiliary device. The specific auxiliary device may be a single auxiliary device or multiple auxiliary devices. The independent operation instruction is transmitted to the control device 30 by a maintenance worker operating the operation board 40.

The control device 30 executes auxiliary operation limiting control to suppress deterioration of the durability of the fuel cell device 100. The auxiliary operation limiting control is described below.

When the control device 30 receives an instruction to restart the fuel cell device 100 (also called a restart instruction) during a shutdown, an instruction to perform a trial run of the fuel cell device 100 (also called a trial run instruction), or an instruction to operate alone, the control device 30 starts auxiliary operation restriction control. The restart instruction is sent to the control device 30 by the user or maintenance company operating a remote control (not shown). The trial run instruction is sent to the control device 30 by the maintenance worker operating the operation board 40.

When the control device 30 starts the auxiliary operation restriction control, it starts monitoring the temperature of the module 1 and the temperature of the reformer 12. In the auxiliary operation restriction control, the control device 30 determines whether the temperature of the module 1 is equal to or higher than a predetermined temperature T0, and whether the temperature of the reformer 12 is equal to or higher than a predetermined temperature T0. The temperature of the module 1 is the central temperature of the module 1 measured by the first temperature measurement unit TC1. The temperature of the reformer 12 is the inlet temperature of the reformer 12 measured by the second temperature measurement unit TC2. The predetermined temperature T0 can be set appropriately, for example, in the range of 60 to 300°C.

The control device 30 controls at least some of the auxiliary devices not to operate when the temperature (also called the measured temperature) T of at least one of the module 1 and the reformer 12 is equal to or higher than a predetermined temperature T0. Operating the auxiliary devices when the operation is stopped and the measured temperature T is equal to or higher than the predetermined temperature T0 may adversely affect the fuel cell device 100, for example, by changing the volume of the fuel cell cells, causing cracks in the fuel cell cells, or by deteriorating the catalyst in the reformer. The auxiliary device operation restriction control can reduce the adverse effects on the fuel cell device 100 caused by the operation of the auxiliary devices when the operation is stopped and the measured temperature T is equal to or higher than the predetermined temperature T0. This makes it possible to suppress the deterioration of the durability of the fuel cell device 100 due to restart, trial operation, independent operation of the auxiliary devices, etc. The independent operation of the auxiliary devices will be described in detail later.

The auxiliary equipment includes a first auxiliary equipment. The first auxiliary equipment includes at least a water pump P3, a fuel pump B1, and a blower B2. The first auxiliary equipment may also include a remote control or an operation board that has a function for operating the fuel cell device 30. In this case, the auxiliary equipment operation restriction control may refer to at least a part of the function of the remote control or the operation board, rather than the entire remote control or the operation board.

The control device 30 may determine whether the temperature of the module 1 is equal to or higher than a first predetermined temperature T1, and whether the temperature of the reformer 12 is equal to or higher than a first predetermined temperature T1. The first predetermined temperature T1 is, for example, 200°C to 300°C.

The control device 30 may control the first auxiliary machine not to operate when the measured temperature T is equal to or higher than the first predetermined temperature T1. In other words, the predetermined temperature T0 in the auxiliary machine operation restriction control may be the first predetermined temperature T1, and at least some of the auxiliary machines whose operation is restricted may be the first auxiliary machine.

For example, by limiting the operation of the fuel pump B1 as the first auxiliary equipment, it is possible to prevent the reforming catalyst in the reformer 12 from deteriorating due to carbon deposition. Also, by limiting the operation of the blower B2 as the first auxiliary equipment, it is possible to prevent high-temperature exhaust gas from being discharged, thereby ensuring the safety of workers, etc. Also, by limiting the operation of the water pump P3 as the first auxiliary equipment, it is possible to prevent damage to the reformer 12 itself.

As described above, when operation is stopped and the measured temperature T is equal to or higher than the first predetermined temperature T1, the first auxiliary is controlled not to operate, thereby reducing adverse effects on the fuel cell device 100. This in turn makes it possible to suppress deterioration in the durability of the fuel cell device 100 due to restart, trial operation, operation of the auxiliary alone, etc.

The first auxiliary device can also be the one that controls the drainage of water using a remote control or an operation board. In this case, it is possible to prevent high-temperature water from being discharged, ensuring the safety of workers, etc.

The control device 30 may further determine whether the temperature of the module 1 is equal to or higher than a second predetermined temperature T2, and whether the temperature of the reformer 12 is equal to or higher than the second predetermined temperature T2. The second predetermined temperature T2 is a temperature set lower than the first predetermined temperature T1, for example, 80°C to 120°C. The control device 30 may further determine whether the temperature of the module 1 is equal to or higher than a third predetermined temperature T3. The third predetermined temperature T3 is a temperature set lower than the second predetermined temperature T2, for example, 60°C to 100°C. In this control, the first auxiliary device may include a remote control.

When the measured temperature T is equal to or higher than the second predetermined temperature T2, or when the temperature of the module 1 is equal to or higher than the third predetermined temperature T3, the control device 30 may not accept and disallow a restart instruction from the remote control or a trial run instruction from the operation board 40. This also disallows the operation of various auxiliary devices, so that, for example, the operation of the fuel pump B1 is indirectly disallowed, thereby preventing the reforming catalyst in the reformer 12 from deteriorating due to carbon deposition. In addition, the operation of the blower B2 is indirectly disallowed, thereby preventing high-temperature exhaust gas from being discharged, and ensuring the safety of workers, etc. As a result, the operation of the auxiliary devices associated with the restart and trial run is disallowed, thereby reducing the adverse effects on the fuel cell device 100. In addition, it is possible to prevent a decrease in the durability of the fuel cell device 100 due to the restart and trial run.

Next, we will explain some examples in which the control device 30 limits the auxiliary unit's independent operation.

When the measured temperature T is equal to or higher than the second predetermined temperature T2, the control device 30 may not accept and not permit an instruction from the operation board 40 to operate the auxiliary devices provided in the fuel gas flow path G and the oxygen-containing gas flow path F alone. This limits the operation of the auxiliary device provided in the fuel gas flow path G as the first auxiliary device, thereby preventing the reforming catalyst in the reformer 12 from deteriorating due to carbon deposition. Furthermore, by limiting the operation of the auxiliary device provided in the oxygen-containing gas flow path F as the first auxiliary device, it is possible to prevent high-temperature exhaust gas from being discharged, thereby ensuring the safety of workers and the like. This makes it possible to prevent a decrease in the durability of the fuel cell device 100 due to the auxiliary device operating alone.

Here, the restriction of the operation of the auxiliary equipment provided in the fuel gas flow path G will be described. For example, as shown in FIG. 1, the fuel gas flow path G is provided with a first solenoid valve V1, a pressure sensor PS, a fuel pump B1, a gas flow meter FM1, and a second solenoid valve V2. In order to check whether the pressure sensor PS detects a predetermined pressure, it is necessary to open the first solenoid valve V1. Therefore, when restricting the operation of the pressure sensor PS, the control device 30 does not restrict the operation of the pressure sensor PS itself, but rather restricts the operation of the first solenoid valve V1. Also, in order to check whether the gas flow meter FM1 detects a predetermined flow rate, it is necessary to open the first solenoid valve V1 and the second solenoid valve V2 and operate the fuel pump B1. Therefore, when restricting the operation of the gas flow meter FM1, the control device 30 does not restrict the operation of the gas flow meter FM1 itself, but rather restricts the operation of the first solenoid valve V1, the second solenoid valve V2, and the fuel pump B1.

As shown in FIG. 1, an air flow meter FM2 and a blower B2 are provided in the oxygen-containing gas flow path F. In order to check whether the air flow meter FM2 detects a predetermined flow rate, it is necessary to operate the blower B2. Therefore, when restricting the operation of the air flow meter FM2, the control device 30 does not restrict the operation of the air flow meter FM2 itself, but rather restricts the operation of the blower B2.

In addition, when the temperature of the module 1 and the reformer 12 is less than the first predetermined temperature T1 and the measured temperature T is equal to or greater than the second predetermined temperature T2, the control device 30 may permit the remaining first auxiliary equipment, such as the water pump P3, to operate independently.

When the measured temperature T is equal to or higher than the first predetermined temperature T1, the control device 30 may not accept and may not permit an instruction to operate the auxiliary devices provided in the fuel gas flow path G, the oxygen-containing gas flow path F, and the reforming water flow path R independently. The auxiliary devices provided in the fuel gas flow path G and the oxygen-containing gas flow path F are as described above. By limiting the operation of the auxiliary devices provided in the reforming water flow path R, damage to the reformer 12 itself can be suppressed. This reduces the adverse effects of independent operation of the fuel pump B1, the first solenoid valve V1, the second solenoid valve V2, the blower B2, the water pump P3, and the like on the fuel cell device 100. This in turn makes it possible to suppress a decrease in the durability of the fuel cell device 100 due to independent operation of the auxiliary devices.

Next, we will explain how the control device 30 restricts the auxiliary equipment from operating alone based on the measurement results of the first temperature measurement unit TC1 and the detection results of the water level sensor WL.

When the temperature of module 1 is equal to or higher than the second predetermined temperature T2, the heat medium in the first heat exchanger 2 may boil due to the exhaust heat from module 1 when the auxiliary equipment provided in the fuel gas flow path G and the oxygen-containing gas flow path F is driven.

However, if the water level sensor WL detects the water level and the heat transfer pump P1 can be driven, the control device 30 may permit an independent operation command to the auxiliary equipment provided in the fuel gas flow path G and the oxygen-containing gas flow path F even if the temperature of the module 1 is equal to or higher than the second predetermined temperature T2.

Since the heat medium is circulated by the heat medium pump P1, boiling of the heat medium in the first heat exchanger 2 due to exhaust heat from the module 1 can be suppressed, and an independent operation command can be received for the auxiliary equipment provided in the fuel gas flow path G and the oxygen-containing gas flow path F. As a result, the operability of the fuel cell device 100 is not impaired while suppressing a decrease in the durability of the fuel cell device 100.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and various modifications and improvements are possible without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 1 Module 11 Fuel cell 12 Reformer B1 Fuel pump B2 Blower P3 Water pump 30 Control device 100 Fuel cell device

Claims (3)

a module including a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas;
a reformer that reforms a raw fuel to generate a fuel gas to be supplied to the fuel cell;
a plurality of auxiliary devices for operating the fuel cell;
A control device that controls the operation of the plurality of accessories,
the control device controls a part of the plurality of auxiliary devices not to operate when the fuel cell is stopped and the temperature of at least one of the module and the reformer is equal to or higher than a predetermined temperature when the fuel cell is to be started;
The plurality of auxiliary devices include a water pump for supplying water to the reformer, a fuel pump for supplying raw fuel to the reformer,
a first auxiliary fuel cell including a fuel pump for supplying a fuel to the fuel cell, and a blower for supplying an oxygen-containing gas to the fuel cell;
With the machine,
The control device determines whether the temperature of the module is equal to or higher than a first predetermined temperature, and
The fuel cell device determines whether or not the temperature of the reformer is equal to or higher than the first predetermined temperature . 2. The fuel cell device according to claim 1, wherein the control device controls the first auxiliary device not to operate when the temperature of at least one of the module and the reformer is equal to or higher than the first predetermined temperature. the control device determines whether the temperature of the module is equal to or higher than a second predetermined temperature that is set lower than the first predetermined temperature, and whether the temperature of the reformer is equal to or higher than the second predetermined temperature;
2. The fuel cell device according to claim 1, wherein the control device controls the fuel pump and blower of the first auxiliary devices not to operate when the temperature of the module and the reformer is lower than the first predetermined temperature and the temperature of at least one of the module and the reformer is higher than the second predetermined temperature.