JP2020136108A - Fuel cell system - Google Patents

Abstract

To provide a fuel cell system that can reliably detect an abnormal path without arranging a branch portion of a first communication path 7 and a combustible gas path 9 at a required height when a drainage path of the fuel cell system is blocked.SOLUTION: A fuel cell system 100 includes a combustor 2, an air supply device 1 that supplies a combustion air to the combustor 2, a fuel cell 4, an exhaust path 5 that discharges a combustion exhaust gas discharged from the combustor 2 to the atmosphere. Further, a first communication path 7, a second communication path 8, and a drainage path 6 are provided with a water storage path 10, and have a water sealing structure in which water is sealed via the paths. A branch portion between a combustible gas path 9 and the first communication path 7, which is a path from the fuel cell 4 to the combustor 2, is configured to be located at the same height as the lower position H in the gravity direction, which is a predetermined height, from a branch portion of the exhaust path 5 and the second communication path 8.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fuel cell system including a combustor, an air supply device for supplying combustion air to the combustor, a fuel cell, and an exhaust path for discharging the combustion exhaust gas discharged from the combustor into the atmosphere.

Conventionally, this type of fuel cell system detects an abnormal route when the drainage route is blocked (see, for example, Patent Document 1).

FIG. 6 shows a conventional fuel cell system 200. As shown in FIG. 6, the fuel cell system includes a hydrogen generator 401 that generates a hydrogen-containing gas from a raw material, and a fuel cell 402 that generates electricity by supplying a hydrogen-containing gas and an oxidizing agent gas generated by the hydrogen generator 401. A combustor 404 that burns the anode exhaust gas discharged from the fuel cell 402 through the combustible gas path 403 and discharges the combustion exhaust gas is provided. The combustion exhaust gas discharged from the combustor 404 passes through the exhaust path 405 and is discharged into the atmosphere.

Further, the fuel cell system 200 connects the water tank 406 for storing the condensed water in which the moisture in the anode exhaust gas is condensed, the combustible gas path 403 and the water tank 406, and the first communication path 407 for passing the condensed water. , A second communication path 408 connecting the exhaust path 405 and the water tank 406 is provided. The condensed water accumulated in the water tank 406 above the predetermined water level is discharged from the drainage path 409.

The first communication path 407, the second communication path 408, and the drainage path 409 form a water-sealing structure in which water is sealed through the water tank 406 by collecting water in at least the water tank 406.

Then, when the controller 411 detects that the combustor 404 has been extinguished by the output from the combustion detector 412, it determines that the combustor 404 is abnormal and stops the operation, and performs at least one operation. It is configured as follows.

Japanese Unexamined Patent Publication No. 2017-147040

In the conventional configuration, when the drainage path is blocked, the height H from the branch portion of the flammable gas path to the branch portion of the exhaust path is secured at a certain level or more in order to detect the abnormal path. There is a need. Specifically, when the maximum pressure loss between the combustor and the fuel cell during operation of the fuel cell system is A (kPa), 1 (kPa) = 102 (mmH ₂ O), so A × 102. It is also expressed as (mm). Therefore, it is preferable that the height H from the branch portion of the flammable gas path to the branch portion of the exhaust path is larger than A × 102 (mm).

However, as the number of small houses increases, the demand for miniaturization of fuel cells increases, and it becomes difficult to make the height H larger than A × 102 (mm).

The present invention solves the problem of detecting an abnormal route when the drainage route is blocked by the flow even when the fuel cell system is miniaturized.

In order to solve the above-mentioned conventional problems, the fuel cell system of the present invention suppresses the anodic exhaust gas discharged from the fuel cell through the flammable gas path when the fluctuation of the combustion air supplied from the air supply device is detected. It is a thing.

According to this, even when a sufficient height H cannot be secured due to the miniaturization of the fuel cell system, it is possible to detect the abnormal route when the drainage route is blocked.

The fuel cell system of the present invention can detect an abnormal path when the drainage path is blocked even when a sufficient height H cannot be secured due to the miniaturization of the fuel cell system. Become.

Configuration diagram of the fuel cell system according to the embodiment of the present invention An example of a configuration diagram of a fuel cell system according to a modification 1 of the present invention. In the embodiment of the present invention, the flow of the drainage route is normal. In the embodiment of the present invention, the drainage path is blocked. In the embodiment of the present invention, the flow of the drainage path is blocked and the water reaches the exhaust path. Configuration diagram of a conventional fuel cell system

The fuel cell system of the first invention comprises a reformer that generates hydrogen-containing gas from a raw material, a fuel cell that generates electricity by supplying the hydrogen-containing gas and an oxidant gas, and a combustible gas path from the fuel cell. A combustor that burns the anode exhaust gas that is discharged and discharges the combustion exhaust gas, an air supply device that supplies combustion air to the combustor, and the combustion exhaust gas that is discharged from the combustor is discharged into the atmosphere. An exhaust path, a first communication path through which condensed water condensed in the combustible gas path flows, and a second communication path connected via the first communication path and a water storage path capable of storing the condensed water. A drainage path provided in the water storage path and draining condensed water accumulated in the water storage path above a predetermined water level from the water storage path and a supply amount of the combustion air supplied from the air supply device to the combustor. The first communication path, the second communication path, and the drainage path have a water-sealing configuration in which the first communication path, the second communication path, and the drainage path are water-sealed at least through the water storage path. The branch portion between the combustible gas path and the first communication path is at the same height as the lower position H in the gravity direction, which is a predetermined height, than the branch portion between the exhaust path and the second communication path. It is configured to be located between.

According to the fuel cell system of the first invention, when the drainage path is blocked and the water stored above the predetermined water level cannot be drained from the water storage path, the water enters the exhaust path and the air supply device is installed. Since the amount of combustion air supplied to the combustor fluctuates, it is possible to reliably detect an abnormality in the flow obstruction of the drainage path.

The fuel cell system of the second invention comprises a reformer that generates hydrogen-containing gas from a raw material, a fuel cell that generates electricity by supplying the hydrogen-containing gas and an oxidant gas, and a combustible gas path from the fuel cell. A combustor that burns the anode exhaust gas that is discharged and discharges the combustion exhaust gas, an air supply device that supplies combustion air to the combustor, and the combustion exhaust gas that is discharged from the combustor is discharged into the atmosphere. An exhaust path, a water tank that stores condensed water condensed in the combustible gas path, a first communication path that connects the combustible gas path and the water tank, and flows the condensed water, and the exhaust path and the water tank. A second communication path for connecting the two, a drainage path for draining condensed water accumulated in the water tank above a predetermined water level from the water tank, and the combustion air supplied from the air supply device to the combustor. The first communication path is connected to the water tank at a position lower than the water level of the water tank, and the first communication path and the second communication path are provided with an air supply amount detecting means for detecting the supply amount of the water. The drainage path has a water-sealed structure in which water is sealed by collecting water in the water tank, and the branch portion between the combustible gas path and the first communication path is the exhaust path. It is configured to be located between the lower position H in the gravity direction, which is a predetermined height, and the same height as the branch portion with the second communication path.

According to the fuel cell system of the second invention, when the drainage path is blocked and the water tank cannot be drained, the moisture enters the exhaust path and the combustion air supplied to the combustor by the air supply device. Since the supply amount of the water fluctuates, it is possible to reliably detect an abnormality in the flow obstruction of the drainage route.

The fuel cell system of the third invention supplies the fuel cell system of the first or second invention to the combustor when the detection value of the air supply amount detecting means exceeds a predetermined fluctuation range. It is equipped with a control unit that limits the supply amount of anode exhaust gas.

According to the fuel cell system of the third invention, when the control unit detects a flow blockage in the drainage path, the supply amount of the anode exhaust gas supplied to the combustor is limited. As a result, the load on the first communication path due to the anode exhaust gas is reduced. As a result, the water level in the first communication path rises, and when water reaches the branch of the first communication path and the flammable gas path, the water flows through the combustible gas path, causing an abnormality in the supply of the anode exhaust gas to the combustor. To do. By detecting the supply abnormality of the anode exhaust gas and stopping the operation of the fuel cell, a highly safe configuration can be realized.

In the fuel cell system of the fourth invention, particularly in the fuel cell system of the third invention, when the control unit detects the fluctuation of the air supplied from the air supply device by the air supply amount detecting means, the said The power generation output of the fuel cell is suppressed to a predetermined threshold value or less, and the anode exhaust gas discharged from the fuel cell via the flammable gas path is suppressed.

According to the fuel cell system of the fourth invention, when the control unit detects a flow blockage in the drainage path, the amount of power generated by the fuel cell is suppressed to a predetermined threshold or less, thereby supplying the anode exhaust gas to the combustor. To limit. As a result, the load on the first communication path due to the anode exhaust gas is reduced. As a result, the water level in the first communication path rises, and when water reaches the branch of the first communication path and the flammable gas path, the water flows through the combustible gas path, causing an abnormality in the supply of the anode exhaust gas to the combustor. To do. By detecting the supply abnormality of the anode exhaust gas and stopping the operation of the fuel cell, a highly safe configuration can be realized. Further, since the supply amount of the anode exhaust gas is suppressed by the power generation amount of the fuel cell to reduce the emission amount of the combustion exhaust gas, it is possible to suppress the influence of the flow blockage of the exhaust path while keeping the fuel cell system stable.

The fuel cell system of the fifth invention, particularly in the fuel cell system of the third invention, includes an on-off valve in the first communication path, and the control unit is supplied from the air supply device by the air supply amount detecting means. When the fluctuation of the combustion air is detected, the on-off valve is closed, and the condensed water collected on the upstream side of the on-off valve of the first communication path becomes the flammable gas path and the first communication path. By reaching the branch portion of the fuel cell, the supply of the anode exhaust gas discharged from the fuel cell through the flammable gas path is suppressed.

According to the fuel cell system of the fifth invention, the control unit closes the on-off valve to dam the condensed water flowing from the flammable gas path to the first communication path with the on-off valve. As a result, the water level in the first communication path rises, and when water reaches the branch of the first communication path and the flammable gas path, the water flows through the combustible gas path, causing an abnormality in the supply of the anode exhaust gas to the combustor. To do. By detecting the supply abnormality of the anode exhaust gas and stopping the operation of the fuel cell, a highly safe configuration can be realized.

In the fuel cell system of the sixth invention, particularly in the fuel cell system of the first to fifth inventions, the air supply amount detecting means is provided between the air supply device and the combustor. It was.

According to the fuel cell system of the sixth invention, the fluctuation of the combustion air supplied from the air supply device to the combustor can be reliably detected by the flow rate detector.

In the fuel cell system of the seventh invention, particularly in the fuel cell systems of the first to fifth inventions, the air supply device includes a fan, the air supply amount detecting means is the rotation speed detecting means of the fan, and the fan. It is configured to detect fluctuations in the combustion air supplied from the air supply device based on the rotation speed detection result of.

According to the fuel cell system of the seventh invention, since the flow rate detector is used as the fan rotation speed detecting means, it is not necessary to provide a new detecting means for detecting fluctuations in the supply amount of combustion air, and the fuel cell system Can be simplified.

The fuel cell system of the eighth invention, particularly in the fuel cell systems of the first to fifth inventions, uses the air supply amount detecting means as the pressure of the combustion air supplied from the air supply device to the combustor. The detector is configured to detect fluctuations in the combustion air supplied from the air supply device based on the pressure detection result of the combustion air.

According to the fuel cell system of the eighth invention, the fluctuation of the combustion air supplied from the air supply device to the combustor is ensured by detecting the pressure of the combustion air supplied from the air supply device to the combustor. Can be detected.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the present embodiment.
(Embodiment)
FIG. 1 shows a configuration diagram of a combustion system according to the first embodiment of the present invention. In FIG. 1, the fuel cell system 0 includes a reformer 3, a fuel cell 4, a flammable gas path 9, a combustor 2, an air supply device 1, an exhaust path 5, a first communication path 7, a water storage path 10, and a second communication. It includes a path 8, a drainage path 6, an air supply amount detecting means 11, and a control unit 20.

A raw material is supplied to the reformer 3 to generate a hydrogen-containing gas. The fuel cell 4 generates electricity using the hydrogen-containing gas generated by the reformer 3 and the oxidant gas.

The combustor 2 burns unreacted fuel gas (hereinafter referred to as anode exhaust gas) discharged from the fuel cell 4 through the flammable gas path 9, and heats the reformer 4 to a temperature suitable for the reforming reaction. .. The combustion exhaust gas generated by the combustion of the anode exhaust gas and the combustion air in the combustor 2 passes through the exhaust path 5 and is discharged into the atmosphere.

In the present embodiment, the combustion air used for combustion of the combustor 2 is supplied by the air supply device 1.

Further, the fuel cell system 100 includes an air supply amount detecting means 11. The air supply amount detecting means 11 detects fluctuations in the combustion air supplied from the air supply device 1. The air supply amount detecting means 11 is configured to provide a flow meter or a pressure gauge in the path for supplying combustion air from the air supply device 1 to the combustor 3 to detect the flow rate and fluctuation range of the combustion air. it can. As a result, fluctuations in the combustion air supplied from the air supply device 1 to the combustor 2 can be reliably detected.

Alternatively, the flow rate or fluctuation of the combustion air may be detected by the rotation speed of the fan provided in the air supply device 1. When the air supply amount output means 11 is used as the fan rotation speed detecting means, it is not necessary to provide a new detecting means for detecting fluctuations in the supply amount of combustion air, and the fuel cell system 100 can be simplified.

Further, the condensed water branched from the first communication path 7 at the flammable gas path 9 and the branch portion and condensed in the combustible gas path 9 flows through the first distribution path 7, and is below the first communication path 7 and the gravity direction. It is stored in the connected water storage path 10. Then, the anodic exhaust gas that has been condensed to remove water is passed through the flammable gas path 9 and supplied to the combustor 2.

Further, the exhaust path 5 and the branch portion are branched from the second communication path 8, and the condensed water condensed in the exhaust path 5 passes through the second distribution path 8 and is connected to the second communication path 8 on the lower side in the gravity direction. It is stored in the water storage route 10.

Further, the water storage path 10 is provided with a drainage path 6, and the condensed water collected in the water storage path 6 above the predetermined water level is drained from the drainage path 6.

As described above, the first communication path 7, the second communication path 8, and the drainage path 6 form a water-sealing structure in which water is sealed through at least the water storage path 10.

The control unit 20 detects fluctuations in the combustion air supplied from the air supply device 1 detected by the air supply amount detecting means 11 and performs control described later. The control unit 20 may be composed of one or more electronic circuits including a semiconductor device, a semiconductor integrated circuit (IC), or an LSI (large scale integration). Further, all or part of the functions or operations of the controller 20 can also be executed by software processing. In this case, the software (program) is recorded on one or more non-temporary recording media selected from ROMs, optical disks, hard disk drives, etc., and the software is executed by a processor. When so, the software causes the processor and peripheral devices to perform certain functions within the software.

The operation and operation of the fuel cell system 100 configured as described above will be described below.

First, a raw material such as natural gas or LPG is supplied to the reformer 3 by a raw material blower (not shown) which is a raw material supply unit for supplying the raw material. In the reformer 3, the supplied raw material is steam reformed in a steam atmosphere to generate a hydrogen-containing gas containing a large amount of hydrogen. The generated hydrogen-containing gas is supplied to the fuel electrode side (anode side) of the fuel cell 4. Further, air is supplied as an oxidant gas to the oxidant electrode side (cathode side) of the fuel cell 4.

In the fuel cell 4, a predetermined reaction is carried out using the fuel gas and the oxidant gas supplied in this way. As a result, power is generated and heat is generated. This heat is recovered by the cooling water flowing through the fuel cell.

Here, the anode exhaust gas, which is an unreacted fuel gas discharged from the fuel cell 4 without being used for the reaction, is supplied to the combustor 2 and used for combustion. The reformer 3 is heated by the combustion heat generated in the combustor 2. As a result, the steam reforming reaction is carried out while the reaction section is kept at a predetermined temperature.

The anode exhaust gas discharged from the fuel cell 4 contains water, and is sent to the branch portion of the first communication path 7 and the flammable gas path 9 in the process of passing through the first communication path 7, and is sent to the branch portion of the first communication path 7. Condensed at the branch portion of the combustible gas path 9 and the condensate, the condensed water passes through the first communication path 7 and is stored in the water storage path 10. The anode exhaust gas from which water has been removed is sent to the combustor 2 and reused as fuel gas.

Next, the detailed configuration of the drainage route will be described with reference to FIG. FIG. 3 shows an outline of the drainage route of the fuel cell system 100 in the present embodiment. In FIG. 3, a condenser 15 is provided at a branch portion between the flammable gas path 9 and the first communication path 7. The condensed water condensed by the condenser 15 passes through the first communication path 7 and is stored in the water storage path 10.

FIG. 3 shows a state in which the drainage path 6 is not blocked. The drainage route 6 is connected to the water storage route 10. Further, the branching points of the first communication path 7 and the flammable gas path 9 and the branching points of the exhaust path 5 and the second communication path 8 are located higher than the branching points of the drainage path 6 and the water storage path 10 (in the direction of gravity). It is provided above), and the branch point between the drainage path 6 and the water storage path 10 is blocked with condensed water.

In this way, by collecting water in the water storage path 10, a water sealing configuration is realized in which the first communication path 7, the second communication path 8, and the drainage path 6 are water-sealed via the water storage path 10. ..

When the flow of the drainage path 6 is not blocked by the water-sealed configuration configured as described above, the anode exhaust gas is burned by the combustor 2 and the combustion exhaust gas is discharged into the atmosphere from the exhaust path 5. , The anode exhaust gas is configured so as not to flow from the first communication path 7 to the drainage path 6. Similarly, it is configured so that the combustion exhaust gas does not flow into the drainage path 6.

In the present embodiment, the branch portion of the first communication path 7 and the flammable gas path 9 is between a position lower than the branch portion of the exhaust path 5 and the second communication path 8 by a predetermined height H and the same height. It is provided. As an example, the height H is the height obtained by converting the maximum pressure loss between the combustor 2 and the flammable gas path 9 from A (kPa) during operation of the fuel cell system, for example, 1 (kPa) = 102 (mmH ₂ ). Since it is O), the height from the branch portion of the first communication path 7 and the flammable gas path 9 to the branch portion of the exhaust path 5 and the second communication path 8 is expressed as H = A × 102 (mm). The height H from the branch of the 1st communication path 7 and the flammable gas path 9 to the branch of the exhaust path 5 and the 2nd communication path 8 is within A × 102 (mm) of the 1st communication path 7 and the flammable gas path. A branch of 9 is provided.

FIGS. 4 and 5 show a state in which the drainage path 6 is blocked.

Here, it is assumed that the drainage path 6 is blocked by the flow during the operation of the fuel cell system 100. As shown in FIG. 4, when the drainage path 6 is blocked, the condensed water condensed from the branch portion of the first communication path 7 and the flammable gas path 9 flows through the first communication path 7 and stores water. It is supplied to the route 10 and the water level of the water storage route 10 and the water level of the second communication route 8 rise.

Then, as shown in FIG. 5, when the water level of the second communication path 8 reaches the branch portion of the exhaust path 5 and the second communication path 8, the supply flow rate of the combustion air supplied from the air supply device 1 fluctuates. To do.

In the present embodiment, when the air supply amount detecting means 11 detects the fluctuation of the combustion air supplied from the air supply device 1 by the air supply amount detecting means 11, the control unit 20 sets, for example, the power generation output in advance. By suppressing the value to the threshold value or less, the anode exhaust gas flowing from the branch portion of the first communication path 7 and the combustible gas path 9 to the combustor 2 can be suppressed. Further, when the detected value of the air supply amount detecting means 11 exceeds a predetermined fluctuation range, the control unit 20 executes a control instruction for suppressing the power generation amount of the fuel cell 4 to a threshold value set in advance or less.

As a result, the load on the first communication path 7 due to the anode exhaust gas discharged from the fuel cell 4 is suppressed, so that the water level of the first communication path 7 rises, and the first communication path 7 and the flammable gas path 9 Water reaches the branch of. Water passes through the combustible gas path 9, and an abnormality in the supply of the anode exhaust gas to the combustor 2 occurs. The control unit 20 detects the abnormal supply of the anode exhaust gas and stops the operation of the fuel cell 4, so that a highly safe configuration can be realized. Further, since the supply amount of the anode exhaust gas is suppressed by the power generation amount of the fuel cell 4 and the emission amount of the combustion exhaust gas is reduced, the influence of the flow blockage of the exhaust path 5 is suppressed while keeping the fuel cell system 100 stable. Can be done.

Alternatively, water may enter the flammable gas path 9 and be supplied to the combustor 2 to stop combustion in the combustor 2. Also in this case, the control unit 20 detects the misfire of the combustor 2 and stops the fuel cell 4, so that a highly safe configuration can be realized.
(Modification example 1)
Modification 1 of the present invention will be described with reference to FIG.

The fuel cell system 101 of the first modification is the one in which the water storage path 10 of the embodiment described above is replaced with the water tank 12.

Here, the first communication path 7 and the water tank 12 are connected at a position lower than the water level of the water stored in the water tank 12. At the branching portion of the first communication path 7 and the flammable gas path 9, the condensed water condensed in the combustible gas path 9 passes through the first communication path 7 and is stored in the water tank 12. Further, the water tank 12 is connected to the second communication path 8, and the rainwater flowing from the exhaust path 5 and the condensed water condensed from the combustion exhaust gas pass through the second communication path 8 to the water tank 12. Can be saved. A drainage path 6 is connected to the water tank 12, and water accumulated in the water tank 12 above a predetermined water level is discharged.

In this way, a water-sealing configuration is realized in which the first communication path 7, the second communication path 8, and the drainage path 6 are water-sealed by collecting water in the water tank 12.

When the flow of the drainage path 6 is not blocked by the water-sealed configuration configured as described above, the anode exhaust gas is burned by the combustor 2 and the combustion exhaust gas is discharged into the atmosphere from the exhaust path 5. , The anode exhaust gas is configured so as not to flow from the first communication path 7 to the drainage path 6.

In the first modification, the branch portion of the first communication path 7 and the flammable gas path 9 is located between a position lower than the branch portion of the exhaust path 5 and the second communication path 8 by a predetermined height H and the same height. It is provided. As an example, the height H is the height obtained by converting the maximum pressure loss between the combustor 2 and the flammable gas path 9 from A (kPa) during operation of the fuel cell system, for example, 1 (kPa) = 102 (mmH ₂ ). Since it is O), the height from the branch portion of the first communication path 7 and the flammable gas path 9 to the branch portion of the exhaust path 5 and the second communication path 8 is expressed as H = A × 102 (mm). The height H from the branch of the 1st communication path 7 and the flammable gas path 9 to the branch of the exhaust path 5 and the 2nd communication path 8 is within A × 102 (mm) of the 1st communication path 7 and the flammable gas path. A branch of 9 is provided.

Also in the first modification, the flow blockage of the drainage path 5 can be detected by the same mechanism as that of the above-described embodiment.

It is assumed that the drainage path 6 is blocked during the operation of the fuel cell system 101. When the drainage path 6 is blocked, the condensed water condensed from the branch portion of the first communication path 7 and the flammable gas path 9 is supplied to the water tank 12 through the first communication path 7 and is supplied to the water tank 12. The water level of the communication route 8 rises.

Then, when the water level of the second communication path 8 reaches the branch portion of the exhaust path 5 and the second communication path 8, the supply flow rate of the combustion air supplied from the air supply device 1 fluctuates.

In the first modification, when the air supply amount detecting means 11 detects the fluctuation of the combustion air supplied from the air supply device 1 by the air supply amount detecting means 11, the control unit 20 sets, for example, the power generation output in advance. By suppressing the value to the threshold value or less, the anode exhaust gas flowing from the branch portion of the first communication path 7 and the combustible gas path 9 to the combustor 2 can be suppressed. Further, when the detected value of the air supply amount detecting means 11 exceeds a predetermined fluctuation range, the control unit 20 executes a control instruction for suppressing the power generation amount of the fuel cell 4 to a threshold value set in advance or less.

As a result, the load on the first communication path 7 due to the anode exhaust gas discharged from the fuel cell 4 is suppressed, so that the water level of the first communication path 7 rises, and the first communication path 7 and the flammable gas path 9 Water reaches the branch of. Water passes through the combustible gas path 9, and an abnormality in the supply of the anode exhaust gas to the combustor 2 occurs. The control unit 20 detects the abnormal supply of the anode exhaust gas and stops the operation of the fuel cell 4, so that a highly safe configuration can be realized. Further, since the supply amount of the anode exhaust gas is suppressed by the power generation amount of the fuel cell 4 and the emission amount of the combustion exhaust gas is reduced, the influence of the flow blockage of the exhaust path 5 is suppressed while keeping the fuel cell system 100 stable. Can be done.

Alternatively, water may enter the flammable gas path 9 and be supplied to the combustor 2 to stop combustion in the combustor 2. Also in this case, the control unit 20 detects the misfire of the combustor 2 and stops the fuel cell 4, so that a highly safe configuration can be realized.
(Modification 2)
Modification 2 of the present invention will be described with reference to FIG.

The fuel cell system 100 of the second modification is provided with an on-off valve 14 in the first communication path 7 of the embodiment described above. Since other configurations are the same as those of the above-described embodiment, detailed description thereof will be omitted.

Also in the fuel cell system 100 of the second modification, when the flow of the drainage path 6 is not blocked, the anode exhaust gas is burned by the combustor 2, and the combustion exhaust gas is discharged into the atmosphere from the exhaust path 5. The anode exhaust gas is configured so as not to flow from the first communication path 7 to the drainage path 6.

In the second modification, the branch portion of the first communication path 7 and the flammable gas path 9 is located between a position lower than the branch portion of the exhaust path 5 and the second communication path 8 by a predetermined height H and the same height. It is provided. As an example, the height H is the height obtained by converting the maximum pressure loss between the combustor 2 and the flammable gas path 9 from A (kPa) during operation of the fuel cell system, for example, 1 (kPa) = 102 (mmH ₂ ). Since it is O), the height from the branch portion of the first communication path 7 and the flammable gas path 9 to the branch portion of the exhaust path 5 and the second communication path 8 is expressed as H = A × 102 (mm). The height H from the branch of the 1st communication path 7 and the flammable gas path 9 to the branch of the exhaust path 5 and the 2nd communication path 8 is within A × 102 (mm) of the 1st communication path 7 and the flammable gas path. A branch of 9 is provided.

Also in the second modification, the flow blockage of the drainage path 5 can be detected by the same mechanism as that of the above-described embodiment.

When the drainage path 6 is blocked, the condensed water condensed from the branch portion of the first communication path 7 and the flammable gas path 9 is supplied to the water storage path 10 through the first communication path 7 to store water. The water level of the route 10 and the water level of the second communication route 8 rise.

When the water level of the second communication path 8 reaches the branch portion of the exhaust path 5 and the second communication path 8, the supply flow rate of the combustion air supplied from the air supply device 1 fluctuates.

In the second modification, when the control unit 20 detects the fluctuation of the combustion air supplied from the air supply device 1 by the air supply amount detecting means 11, the control unit 20 closes the on-off valve 14 and enters from the flammable gas path 9. The condensate water flowing through the first communication path 7 of the above is dammed up by an on-off valve. As a result, when the water level of the first communication path 7 rises and the water reaches the branch portion of the first communication path 7 and the flammable gas path 9, the water passes through the combustible gas path 9 and the anode exhaust gas to the combustor 2 is exhausted. Supply error occurs. The control unit 20 detects an abnormality in the supply of the anode exhaust gas and stops the operation of the fuel cell 4, so that a highly safe configuration can be realized.

Alternatively, water may enter the flammable gas path 9 and be supplied to the combustor 2 to stop combustion in the combustor 2. Also in this case, the control unit 20 detects the misfire of the combustor 2 and stops the fuel cell 4, so that a highly safe configuration can be realized.

In the above description, the operation in the configuration in which the on-off valve 14 is provided in the fuel cell system 100 of the embodiment has been described, but the operation is not limited to this. For example, it can be applied to the fuel cell system 101 of the first modification in which the water tank 12 is provided instead of the water storage path 10, and the same effect can be obtained.

From the above description, many improvements and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as an example only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the present invention. The details of its structure and / or function can be substantially changed without departing from the spirit of the present invention.

As described above, the combustion system according to the present invention can be applied to, for example, a cogeneration system.

1 Air supply device 2 Combustor 3 Reformer 4 Fuel cell 5 Exhaust route 6 Drainage route 7 1st communication route 8 2nd communication route 9 Combustible gas route 10 Water storage route 11 Air supply amount detection means 12 Water tank 14 On-off valve 15 Condenser 20 Control 100, 101 Fuel cell system

Claims (8)

A reformer that produces hydrogen-containing gas from raw materials,
A fuel cell to which the hydrogen-containing gas and the oxidant gas are supplied to generate electricity,
A combustor that burns the anode exhaust gas discharged from the fuel cell through the flammable gas path and discharges the combustion exhaust gas.
An air supply device that supplies combustion air to the combustor,
An exhaust path for discharging the combustion exhaust gas discharged from the combustor into the atmosphere,
The first communication path through which the condensed water condensed in the flammable gas path flows, and
The first communication path and the second communication path connected via a water storage path capable of storing the condensed water, and
A drainage path provided in the water storage path and draining condensed water accumulated in the water storage path above a predetermined water level from the water storage path,
An air supply amount detecting means for detecting the supply amount of the combustion air supplied from the air supply device to the combustor is provided.
The first communication route, the second communication route, and the drainage route have a water-sealing configuration in which water is sealed through at least the water storage route.
The branch portion between the combustible gas path and the first communication path is between the same height as the lower position H in the gravity direction, which is a predetermined height, than the branch portion between the exhaust path and the second communication path. A fuel cell system that is configured to be located in. A reformer that produces hydrogen-containing gas from raw materials,
A fuel cell to which the hydrogen-containing gas and the oxidant gas are supplied to generate electricity,
A combustor that burns the anode exhaust gas discharged from the fuel cell through the flammable gas path and discharges the combustion exhaust gas.
An air supply device that supplies combustion air to the combustor,
An exhaust path for discharging the combustion exhaust gas discharged from the combustor into the atmosphere,
A water tank that stores condensed water condensed in the flammable gas path,
A first communication path that connects the flammable gas path and the water tank and circulates the condensed water,
A second communication path connecting the exhaust path and the water tank,
A drainage route for draining condensed water accumulated in the water tank above a predetermined water level from the water tank,
An air supply amount detecting means for detecting the supply amount of the combustion air supplied from the air supply device to the combustor is provided.
The first communication path is connected to the water tank at a position lower than the water level of the water tank, and the first communication path, the second communication path, and the drainage path are such that water collects in the water tank. It has a water-sealed structure that is water-sealed by
The branch portion between the combustible gas path and the first communication path is between the same height as the lower position H in the gravity direction, which is a predetermined height, than the branch portion between the exhaust path and the second communication path. A fuel cell system that is configured to be located in. The first or second aspect of the present invention, wherein the control unit for limiting the supply amount of the anode exhaust gas supplied to the combustor when the detection value of the air supply amount detecting means exceeds a predetermined fluctuation range is provided. Fuel cell system. When the control unit detects the fluctuation of the combustion air supplied from the air supply device by the air supply amount detecting means, the control unit suppresses the power generation output of the fuel cell to a predetermined threshold value or less, and the fuel cell is said to be said. The fuel cell system according to claim 3, wherein the anode exhaust gas discharged via a flammable gas path is suppressed. An on-off valve is provided in the first communication path.
When the control unit detects the fluctuation of the combustion air supplied from the air supply device by the air supply amount detecting means, the control unit closes the on-off valve and upstream of the on-off valve of the first communication path. When the condensed water collected on the side reaches the branch portion between the combustible gas path and the first communication path, the supply of the anode exhaust gas discharged from the fuel cell via the combustible gas path is suppressed. Item 3. The fuel cell system according to item 3. The fuel cell system according to any one of claims 1 to 5, wherein the air supply amount detecting means is a flow rate detector provided between the air supply device and the combustor. The air supply device includes a fan, the air supply amount detecting means is the rotation speed detecting means of the fan, and the combustion air supplied from the air supply device based on the rotation speed detection result of the fan. The fuel cell system according to any one of claims 1 to 5, which detects the fluctuation of the above. The air supply amount detecting means is a pressure detector for the combustion air supplied from the air supply device to the combustor, and is supplied from the air supply device based on the pressure detection result of the combustion air. The fuel cell system according to any one of claims 1 to 5, which detects fluctuations in the combustion air.

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