JP6051402B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a configuration of a fuel cell system including a tank for storing moisture contained in exhaust gas discharged from a fuel cell.

  A fuel cell is a device that generates water and heat by generating electricity through an electrochemical reaction between a fuel gas containing hydrogen and an oxidant gas containing oxygen. Fuel cells are attracting attention because of their high power generation efficiency because they can be directly extracted as electrical energy without converting the chemical energy of the fuel into mechanical energy, but it cannot be said that the cost reduction is still progressing sufficiently. As the fuel cell system has become widespread, it has been a major challenge to reduce costs.

  In addition, in a fuel cell system including a fuel cell, a fuel gas (hydrogen gas) used as a fuel at the time of power generation is not provided as a general infrastructure, and thus usually includes a hydrogen generator. In the hydrogen generator, a fuel gas rich in hydrogen is generated by a steam reforming reaction in which a raw material gas such as natural gas and water are used. The steam reforming reaction proceeds by being heated by a burner built in the hydrogen generator. In this burner, combustion is performed by supplying raw material gas or fuel gas that has not been used for power generation discharged from the fuel cell (hereinafter referred to as off-fuel gas).

  A fuel cell power generation device is known that includes a condensed water tank that collects the condensed water of off-oxidant gas discharged from the fuel cell main body and off-combustion gas discharged from the burner (for example, (See Patent Document 1 and Patent Document 2). Patent Document 1 discloses a configuration in which the inside of a condensed water tank is separated by a partition wall, and when the exhaust port is blocked, the water level in the condensed water tank is lowered, and the fuel cell system is stopped by detecting the lowered water level. It is possible to suppress an increase in the internal pressure of the fuel cell device. Patent Document 2 discloses a fuel cell that has been performed only by a conventional fuel cell cooling pump by a configuration in which a fuel cell cooling water circulation pump and a supply pump of a fuel processor circuit are operated at the time of initial water filling to the cooling water circulation circuit of the fuel cell. It is possible to fill the cooling water circulation circuit with a water filling without air biting in a short time.

International Publication No. 2011/093066 JP 2011-1119045 A

  By the way, referring to the condensed water tank disclosed in Patent Literature 1 and Patent Literature 2, the following configuration is obtained. In other words, the condensed water tank is supplied with water from a supply path arranged vertically above the condensed water tank, and an open space is provided above the condensed water tank. It is configured to drop water. And in order to collect | recover condensed water from off combustion gas and off oxidant gas, a condensed water tank becomes a structure connected with an off combustion gas path | route and an off oxidant gas path | route. Here, in a general fuel cell system, water necessary for operation of the fuel cell system can be obtained by reusing condensed water generated during power generation.

However, when operating when the fuel cell system is installed (for example, when operating for the first time after installation, or after draining water for maintenance, etc.), water necessary for the operation of the fuel cell system is stored in the condensate tank. It is necessary to supply water. Conventionally, the water pressure of city water and automatic water supply using city water are used. However, after automatic water supply using city water tap pressure, it was necessary to seal the city water with a shut-off valve (solenoid valve), which caused the cost to increase. In order to make it available for operation, it is necessary to design the city water to be used and the capacity of the water purifier to be large, so that simplification of configuration, space saving, and power saving have been problems.

  On the other hand, using purified water that can be used to operate the fuel cell system for water supply to the condensate tank, and opening the water supply port manually (hereinafter referred to as “manual water supply”), it is closed. It becomes possible to abolish the valve and downsize the water purifier. However, if the water supply port is forgotten to be closed, off-combustion gas or off-oxidant gas leaks from the fuel cell system through the open space above the condensed water tank. In addition, when the exhaust section is blocked or is closed to the closed position (a state where the exhaust gas is not completely blocked but the flow of the exhausted gas is hindered), the off-combustion gas and the off-oxidation are supplied via the supply path. The inventors of the present application have found that there is a problem that the agent gas leaks from the fuel cell system.

  As described above, in the fuel cell system in which water is supplied by manual water supply, the present invention can simplify the configuration of the fuel cell system, achieve space saving and power saving, and can be operated efficiently. The purpose is to provide a power generation system.

In order to solve the above conventional problems, a fuel cell system according to the present invention includes:
A fuel cell that generates power using oxidant gas and fuel gas;
A condensed water tank for storing condensed water generated by condensing water vapor contained in at least one of off-oxidant gas or off-fuel gas discharged from the fuel cell; and
A water supply port whose upper end is arranged vertically above the condensate water tank, and a supply path for supplying purified water from the water supply port to the condensate water tank;
In a fuel cell system comprising:
An exhaust path for discharging off gas to the outside of the fuel cell system is provided,
The condensed water tank includes a first water storage unit to which condensed water is supplied,
The lower end of the supply path connected to the condensate tank is disposed in the first water storage section below the first water level that is set in advance so as to reach when water is supplied by manual water supply. It is comprised, and it is comprised so that the sealing pressure by the hydraulic head difference equivalent to the distance of the perpendicular direction of the uppermost part of a supply path and the lower end of a supply path may become larger than a predetermined 1st pressure.

  Here, the first pressure is the off-oxidant gas or the off-fuel gas when the exhaust path is blocked or partially blocked (not completely closed but the flow of the exhausted gas is hindered). The pressure is set so that at least one of the off-gases does not leak to the outside of the fuel cell system via the supply path, and is set in advance through experiments, simulations, or the like.

  As a result, water supply to the fuel cell system is manually performed from the water supply port provided in the condensate water tank, and even if the water supply port is forgotten to close, the water stored in the condensate water tank causes the lower end of the supply path to Since it is sealed with water, it is possible to prevent the off-fuel gas and off-oxidant gas from leaking out of the fuel cell system through the open space above the condensed water tank. In addition, even in the case where the exhaust part is blocked or closed in the middle of closing, the sealing pressure due to the water head difference corresponding to the vertical distance between the uppermost part of the supply path and the lower end of the supply path is higher than the predetermined first pressure. Because it is configured to be large, the fuel cell off-oxidant gas or off-fuel gas leaks to the outside of the fuel cell system through the water supply port without exceeding the sealing pressure due to the head difference in the supply path. It is possible to prevent exit.

  According to the fuel cell system of the present invention, the lower end of the supply path is sealed with water by purified water stored in the condensate tank with manual water supply, so that the exhaust gas of the fuel cell is removed from the fuel cell system via the water supply port. Leakage can be prevented. Therefore, compared with the conventional fuel cell system, it is possible to simplify the configuration without adding a shut-off valve and increasing the size of the water purifier, and to achieve space saving and power saving. Become.

1 is a block diagram schematically showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention. Schematic showing the water level in the condensed water tank of part A in FIG. 1 and the height of the component parts Schematic which shows the structure of the water supply port of B section in FIG. 1, and a supply path | route. FIG. 2 is a block diagram schematically showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention. FIG. 3 is a block diagram schematically showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention. Block diagram schematically showing a schematic configuration of a fuel cell system according to Embodiment 4 of the present invention. FIG. 5 is a block diagram schematically showing a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention.

The present invention is
A fuel cell that generates power using oxidant gas and fuel gas;
A condensed water tank for storing condensed water generated by condensing water vapor contained in at least one of off-oxidant gas or off-fuel gas discharged from the fuel cell; and
A water supply port whose upper end is arranged vertically above the condensate water tank, and a supply path for supplying purified water from the water supply port to the condensate water tank;
In a fuel cell system comprising:
An exhaust path for discharging off gas to the outside of the fuel cell system is provided,
The condensed water tank includes a first water storage unit to which condensed water is supplied,
The lower end of the supply path connected to the condensate tank is disposed in the first water storage section below the first water level that is set in advance so as to reach when water is supplied by manual water supply. It is comprised, It is characterized by comprising so that the sealing pressure by the hydraulic head difference corresponded to the distance of the perpendicular direction of the uppermost part of a supply path and the lower end of a supply path may become larger than a predetermined 1st pressure.

  With this configuration, it is possible to prevent the off-oxidant gas or off-fuel gas of the fuel cell from leaking out of the fuel cell system through the water supply port. In addition, compared to conventional fuel cell systems, the configuration can be simplified without adding a shut-off valve and increasing the size of the water purifier, and space and power can be saved. Become.

The water level sensor further detects the water level in the condensed water tank,
The lower end of the supply path connected to the condensed water tank may be configured to be disposed below the second water level detected by the water level sensor in the vertical direction. With this configuration, the water level sensor can detect the water level in the condensed water tank before it becomes lower than the lower end of the supply path.

Further, the fuel cell system may be configured to stop when the water level detected by the water level sensor becomes lower than the second water level. With this configuration, even if the water level in the condensate tank drops, the fuel cell system is stopped before the off-oxidant gas or off-fuel gas of the fuel cell leaks from the fuel cell system through the water supply port. Is possible.

Moreover, it is connected to the drainage port of the condensed water tank, and further comprises a first drainage path for discharging water stored inside the first water reservoir to at least the outside of the first water reservoir,
The condensed water tank further includes a second water storage unit that is in communication with the first water storage unit and configured to seal the gas of the first water storage unit,
You may be comprised so that the lower end of the supply path connected to a condensed water tank may be arrange | positioned at the 1st water storage part of the downward direction perpendicular | vertical rather than a drain outlet. With this configuration, it is possible to prevent the off-oxidant gas or off-fuel gas of the fuel cell from leaking out of the fuel cell system through the water supply port.

Furthermore, a gas supplier for supplying an oxidant gas or fuel gas to the fuel cell;
A housing in which at least a fuel cell, a condensed water tank, and a gas supply unit are housed and an exhaust part for exhausting off-gas is formed;
Further comprising
One end of the exhaust path is connected to the first water storage part of the condensed water tank, and the other end is connected to the exhaust part.
The condensed water tank includes a first condensed water tank provided with a first water storage section, and a first drainage path for discharging water stored in the first water storage section to at least the outside of the first water storage section. A second condensate tank that communicates with the first condensate tank and includes a second water reservoir,
The second condensed water tank stores condensed water supplied from the exhaust part, and includes a water seal part that seals water so that exhaust gas from the exhaust part is not exhausted.
The 2nd drainage channel for discharging the water stored inside the 2nd water storage part to the exterior of the 2nd water storage part may be connected to the 2nd condensed water tank. With this configuration, it is possible to prevent the lower end of the supply path from becoming lower than the water level even when the exhaust part is blocked or partially blocked, and the off-oxidant gas or off-fuel gas of the fuel cell is supplied to the water supply port. It is possible to prevent leakage to the outside of the fuel cell system.

A gas supply for supplying an oxidant gas or fuel gas to the fuel cell;
A housing in which at least a fuel cell, a condensed water tank, and a gas supply unit are housed and an exhaust part for exhausting off-gas is formed;
A water recovery tank that has a water seal portion that stores condensed water supplied from the exhaust portion and seals water so that exhaust from the exhaust portion does not flow,
Further comprising
The condensate tank is formed in the condensate tank with a second water reservoir formed across the first water reservoir and the partition wall, and the first water reservoir and the second water reservoir are formed below the condensate water tank. A communication portion configured to communicate with each other,
One end of the exhaust path is connected to the condensate water tank, the other end is connected to the exhaust part, and the water recovery tank communicates with the condensate tank via the first drainage path and is stored inside. A third drainage path for discharging the generated water to the outside of the water recovery tank may be connected.

  Here, the lower part of the condensed water tank means that it is located below the drain port of the condensed water tank in the vertical direction.

  With this configuration, it is possible to prevent the lower end of the supply path from becoming lower than the water level even when the exhaust part is blocked or partially blocked, and the off-oxidant gas or off-fuel gas of the fuel cell is supplied to the water supply port. It is possible to prevent leakage to the outside of the fuel cell system.

Furthermore, the pressure detector which detects that the pressure of the 1st water storage part of a condensed water tank became more than the predetermined 2nd pressure is further provided, and the distance of the perpendicular direction of the uppermost part of a supply path and the lower end of a supply path The sealing pressure due to the water head difference corresponding to may be configured to be larger than the second pressure. With this configuration, even if the exhaust part is blocked or partially blocked, it is possible to detect with the pressure detector before the water level at the lower end of the supply path becomes higher than the second pressure.

  Further, the fuel cell system may be configured to stop when the pressure detected by the pressure detector becomes higher than the second pressure. With this configuration, before the pressure at the time when the exhaust section is closed or halfway blocked becomes higher than the sealing pressure due to the water head difference corresponding to the vertical distance between the upper end of the supply path and the lower end of the supply path. In addition, the fuel cell system can be stopped and the off-oxidant gas or off-fuel gas of the fuel cell can be prevented from leaking outside the fuel cell system through the water supply port.

  Hereinafter, embodiments of the present invention will be specifically exemplified. In all the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Further, in all the drawings, only components necessary for explaining the present invention are extracted and illustrated, and other components are not illustrated. Furthermore, the present invention is not limited to the following embodiment.

(Embodiment 1)
FIG. 1 is a block diagram schematically showing a schematic configuration of a fuel cell system 100 according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a fuel cell system 100 according to Embodiment 1 of the present invention includes a hydrogen generator 1, a fuel cell 5, a blower 6, an oxidant gas path 7, a first off-oxidant gas path 8, and an off-state. Combustion gas condensed water path 10, supply path 12 for supplying water, condensed water tank 13, exhaust gas heat exchanger 18, exhaust air heat exchanger 19, water supply port 21, first drainage path 22, and water purifier 32 are provided. ing.

  The hydrogen generator 1 has a reformer 1a and a combustor 1b for heating the reformer. An off-fuel gas path 4 b is connected to the combustor 1 b of the hydrogen generator 1. The combustor 1b burns the raw material gas supplied through the off-fuel gas path 4b or the fuel gas that has not been used in the fuel cell 5 to generate off-combustion gas. The off-combustion gas generated in the combustor 1b of the hydrogen generator 1 is heated to the reformer 1a and then discharged to the off-combustion gas path 9, and the fuel cell system is passed through the exhaust gas heat exchanger 18 and the exhaust unit 20. 100 is discharged outside.

  A raw material supply unit 2 and a water supply unit 3 are connected to the reformer 1 a of the hydrogen generator 1. The raw material supply unit 2 is configured to supply a raw material gas while adjusting the flow rate thereof to the reformer 1a. As the raw material supply part 2, for example, a flow rate adjusting valve and a pump may be configured, or a flow rate adjustable pump may be configured. Examples of the source gas include natural gas and LP gas.

  The water supply unit 3 is provided with a water supplier 31 and a water purifier 32 for purifying the condensed water stored in the condensed water tank 13 and supplying it to the reformer 1a. The water supply device 31 may be in any form as long as it is configured to supply condensed water while adjusting the flow rate to the reformer 1a. It may be comprised, and may be comprised with the pump which can adjust flow volume. Since the condensed water stored in the condensed water tank 13 contains some impurities, it is purified through a water purifier 32 made of ion exchange resin or the like and supplied to the water supply unit 3.

The reformer 1a of the hydrogen generator 1 is configured to generate a fuel gas containing hydrogen by causing a reforming reaction between the raw material gas and water (for example, condensed water). The fuel gas generated by the reformer is supplied to the anode (not shown) of the fuel cell 5 through the hydrogen supply path 4a.

  The fuel cell 5 has an anode and a cathode (not shown). As the fuel cell 5, various fuel cells such as a polymer electrolyte fuel cell, a direct internal reforming solid oxide fuel cell, and an indirect internal reforming solid oxide fuel cell can be used.

  In the first embodiment, the hydrogen generator 1 and the fuel cell 5 are separately configured. However, the present invention is not limited to this, and the hydrogen generator 1 and the fuel cell 5 are not limited to this. The fuel cell 5 may be integrally formed. In this case, the hydrogen generator 1 and the fuel cell 5 are configured as one unit covered with a common heat insulating material, and the combustor of the hydrogen generator 1 heats not only the reformer 1a but also the fuel cell 5. . In the direct internal reforming solid oxide fuel cell, the anode of the fuel cell 5 has the function of a reformer, so that the anode of the fuel cell 5 and the reformer 1a of the hydrogen generator 1 are integrated. It may be comprised. Furthermore, since the structure of the fuel cell 5 is the same as that of a general fuel cell, its detailed description is omitted.

  An oxidant gas (air) is supplied from the blower 6 through the oxidant gas path 7 to the cathode of the fuel cell 5. Then, the fuel gas supplied to the anode and the oxidant gas supplied to the cathode react to generate water, and electricity and heat are generated. The fuel gas not used in the fuel cell 5 is supplied as off-hydrogen gas to the combustor 1b of the hydrogen generator 1 through the off-fuel gas path 4b. The oxidant gas that has not been used in the fuel cell 5 is discharged out of the fuel cell system 100 via the first off-oxidant gas path 8, the second off-oxidant gas path 11, and the exhaust unit 20.

  The generated electricity is supplied to an external power load (for example, home electrical equipment) by a power regulator (not shown). The generated heat is recovered by cooling water flowing through a cooling water flow path (not shown).

  The exhaust heat recovery water path 23 is configured to recover heat from the off combustion gas and the off oxidant gas that flow through the off combustion gas path 9 and the first off oxidant gas path 8. That is, it is a path for recovering exhaust gas heat. In the first embodiment, a part of the first embodiment is provided outside the housing 101. An exhaust gas heat exchanger 18 and an exhaust air heat exchanger 19 are provided in the exhaust heat recovery water path 23. Then, the first heat medium in the exhaust heat recovery water path 23 flows through each heat exchanger while exchanging heat with the off-fuel gas and the off-oxidant gas. As the first heat medium, water or an antifreeze liquid (for example, an ethylene glycol-containing liquid) can be used.

  The exhaust gas heat exchanger 18 is provided so that the exhaust heat recovery water path 23 and the off combustion gas path 9 are in contact with each other, and the first heat medium and the off combustion gas path 9 flowing through the exhaust heat recovery water path 23 are provided. It is configured to exchange heat with the off-combustion gas flowing therethrough. In addition, by exchanging heat with the first heat medium in the exhaust gas heat exchanger 18, the water vapor in the off-combustion gas is condensed and condensed water is generated. The generated condensed water is collected in the condensed water tank 13 through the off-combustion gas condensed water path 10. The off-combustion gas after the condensed water is recovered is discharged from the open space above the condensed water tank 13 to the outside of the fuel cell system 100 via the second off-oxidant gas path 11 and the exhaust part 20. With this configuration, only the condensed water in the off-combustion gas is collected in the condensed water tank 13.

The exhaust air heat exchanger 19 is provided so as to contact the exhaust heat recovery water path 23 and the first off-oxidant gas path 8, and the first heat medium that flows through the exhaust heat recovery water path 23 Heat is exchanged with the off-oxidant gas flowing through the first off-oxidant gas path 8. In addition, by exchanging heat with the first heat medium in the exhaust air heat exchanger 19, the water vapor in the off-oxidant gas is condensed and condensed water is generated. The generated condensed water is collected in the condensed water tank 13 via the first off-oxidant gas path 8. The off-oxidant gas after the condensed water is recovered is discharged from the open space above the condensed water tank 13 to the outside of the fuel cell system 100 via the second off-oxidant gas path 11 and the exhaust part 20. With this configuration, only the condensed water in the off-oxidant gas is recovered in the condensed water tank 13.

[Condensate tank configuration]
Next, the structure of the supply path 12, the condensed water tank 13, and the water supply port 21 which are the characterizing parts of this invention is demonstrated using FIG.2 and FIG.

  The condensed water stored in the condensed water tank 13 is configured to be naturally discharged to the outside through the drain port 34 of the first drainage path 22 when the height from the lower surface of the condensed water tank 13 becomes H3 or higher. However, as long as drainage from the condensed water tank 13 is possible, it is not limited to this aspect.

  In the present embodiment, the first drainage path 22 is illustrated in which one end is connected to the drainage port 34 of the condensed water tank 13 and the other end is connected to a sewage pipe outside the fuel cell system 100. If the amount of condensed water from the exhaust gas heat exchanger 18 and the exhaust air heat exchanger 19 can be adjusted so that the condensed water does not overflow from the condensed water tank 13, the first drainage path 22 may not be provided. In this case, the height H3 from the lower surface of the condensed water tank 13 is set as the “first water level” to be supplied by manual water supply, and the height from the lower surface of the condensed water tank 13 is the first water level at the time of manual water supply. Water is supplied up to H3. In the manual water supply, the amount of water supplied in a specification or the like is indicated in liters in advance, or purified water is supplied to a prepared container and supplied to the fuel cell system 100. It is common.

  A partition wall 14 may be formed in the condensed water tank 13. The partition wall 14 separates the first water storage unit 15 and the second water storage unit 16 from the upper surface of the condensed water tank 13 to a height H1 from the lower surface of the condensed water tank 13. In addition, it is not limited to this embodiment, For example, when not providing the 1st drainage channel 22, the partition 14 does not need to be provided.

  The supply path 12 is arranged so that water can be supplied to the condensed water tank 13 from above in the vertical direction via the supply path 12. Further, the lower end (= downstream end) of the supply path 12 is disposed at H <b> 1 which is a position lower than the height H <b> 3 from the lower surface of the condensed water tank 13. The water supply port 21, which is the upper end (= upstream end) of the supply path 12, is configured to supply water to the condensed water tank 13 via the supply path 12, but if water supply to the fuel cell system 100 is possible, It is not limited to this aspect.

In addition, although the water supply port 21 illustrates a funnel type, any mode may be used as long as water can be supplied, and the supply path 12 from the water supply port 21 to the condensed water tank 13 illustrates a mode in which water can be supplied vertically downward. However, as shown to Fig.3 (a), the aspect which can provide a bending part in the middle of the supply path 12, and can suppress the water vapor | steam evaporation from the condensed water tank 13 may be sufficient. Moreover, although the attachment direction of the water supply port 21 illustrates the upward direction in the vertical direction, as shown in FIG. 3B, if water can be supplied to the condensed water tank, an angle of more than horizontal is given to the supply path 12. It only has to be. Further, as shown in FIG. 3C, the supply path 12 may be disposed above the water supply port 21 in the vertical direction, and the uppermost portion of the supply path 12 in that case is a path in the middle of the supply path 12. Therefore, a push-in pump or the like may be used for water supply in this mode. In the condensed water tank 13, a water level sensor 17 for detecting a water level having a height of H2 or less is configured. The water level sensor 17 is exemplified by a float switch, but any mode may be used as long as the water level can be detected. When the water level sensor 17 detects a water level lower than the drain outlet 34 and higher than the communicating portion 33 and having a height H2 or less, the fuel cell system 100 is configured to stop. Here, “second water level”
Indicates the water level at which the water level sensor 17 is below the height H2.

[Operation and effect of fuel cell system]
Next, the operation and effect of the fuel cell system 100 according to the first embodiment will be described with reference to FIGS. 1 and 2A to 2B.

  As shown in FIG. 2A, when purified water is supplied to the condensed water tank 13 of the fuel cell system 100 via the supply path 12, the height from the lower surface of the condensed water tank 13 is H3 or more. Then, the water is naturally discharged through the first drainage path 22. Therefore, the amount of water in the condensed water tank 13 can be kept below a certain level. If the first drainage path 22 is not provided, the amount of water supplied by manual water supply is set to the first water level, that is, the height H3 from the lower surface of the condensed water tank 13, so that the condensed water tank 13 is supplied. The amount of water inside can be kept constant.

  The supply path 12 is arranged so that water can be supplied to the condensed water tank 13 from above in the vertical direction via the supply path 12. Therefore, since water falls naturally by gravity, water supply can be performed efficiently.

  And the supply path 12 is arrange | positioned at H1 which is a position lower than the height H3 from the lower surface of the condensed water tank 13 of the 1st drainage path 22. Therefore, when water is filled to a height H1 or higher after the water supply, the second off-oxidant gas path 8 and the off-combustion gas condensed water path 10 are connected to the second off gas via at least one off-gas path. The off-oxidant gas or the off-fuel gas flowing into the oxidant gas path 11 and the condensed water tank 13 passes through the open space above the condensed water tank 13, the supply path 12, and the water supply port 21, and the fuel cell system 100. It is possible to prevent leakage from the air.

  Further, a water level sensor 17 for detecting a water level of height H2 or less is configured in the condensed water tank 13, and when the water level sensor 17 detects a water level of height H2 or less, the fuel cell system 100 is stopped. It is configured to operate. Thereby, as shown in FIG. 2B, even when the water level is lowered, the off-oxidant gas or the off-fuel gas is supplied to the fuel via the open space above the condensed water tank 13, the supply path 12, and the water supply port 21. It is possible to prevent leakage from the battery system 100. In addition, since purified water is supplied by manual water supply, the water purification function for city water use, which was necessary for automatic water supply using city water, is no longer necessary, and the water purifier can be downsized. Become.

  Moreover, the aspect comprised so that the sealing pressure by the hydraulic head difference corresponded to the distance of the perpendicular direction of the uppermost part of the supply path 12 and the lower end of the supply path 12 may become larger than a predetermined 1st pressure. Is.

  Here, the first pressure is the off-oxidant gas or the off-fuel gas when the exhaust path is blocked or partially blocked (not completely closed but the flow of the exhausted gas is hindered). The pressure is set so that at least one of the off-gases does not leak to the outside of the fuel cell system via the supply path, and is set in advance through experiments, simulations, or the like.

  Therefore, the “first pressure” may be set at a pressure higher than the supply pressure from the blower 6 and the raw material supply unit 2.

(Embodiment 2)
In the second embodiment, the description will focus on the parts different from the first embodiment.

  A fuel cell system 100 according to Embodiment 2 houses a gas supply device that supplies an oxidant gas or a fuel gas to the fuel cell 5, at least a fuel cell 5, a condensed water tank 13, and a gas supply device, and an exhaust gas. A housing 101 having a section 20, a second off-oxidant gas path 11 having one end connected to the first water storage section 15 of the condensed water tank 13 and the other end connected to the exhaust section 20, and a condensed water tank. 13 includes a first condensate water tank 24 having a first water storage unit 15 and a second condensate water tank 25 having a second water storage unit 16 communicating with the first condensate water tank 24 via a first drainage path 22. The second condensate water tank 25 is provided with a water seal portion that stores the condensate water supplied from the exhaust portion 20 and seals the exhaust water from the exhaust portion 20 so that it does not flow. 2nd storage of water stored inside The second drainage path 27 for discharging to the outside of the part 16 is connected to the second condensed water tank 25, and the water head difference corresponding to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12 3 illustrates a mode in which the sealing pressure is configured to be larger than a predetermined first pressure.

  Here, the first pressure is the off-oxidant gas or the off-fuel gas when the exhaust path is blocked or partially blocked (not completely closed but the flow of the exhausted gas is hindered). The pressure is set so that at least one of the off-gases does not leak to the outside of the fuel cell system via the supply path, and is set in advance through experiments, simulations, or the like.

  Therefore, the “first pressure” may be set at a pressure higher than the supply pressure from the blower 6 and the raw material supply unit 2.

  In the second embodiment, the gas supply device is the blower 6 that supplies the oxidant gas or the raw material supply unit 2, but in addition to this, in the case of the fuel cell system 100 that supplies hydrogen directly to the fuel cell. May be a device for supplying hydrogen.

FIG. 4 is a schematic diagram showing a schematic configuration of the fuel cell system 100 according to Embodiment 2 of the present invention.

As shown in FIG. 4 , the fuel cell system 100 according to Embodiment 2 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 1, but the first water storage in the condensed water tank 13. The point which changes the partition 14 which isolate | separates the part 15 and the 2nd water storage part 16 into the 2nd condensed water tank 25 provided with the water seal part which seals water so that the exhaust_gas | exhaustion from the exhaust part 20 may not flow is different. .

The second condensed water tank 25 is configured to communicate the exhaust gas condensed water path 26 of the exhaust unit 20 and the first drainage path 22 of the first condensed water tank 24, and the second drainage path 27 and the first drainage path. 22 is gas-liquid separated in the second condensed water tank 25, so that the off-oxidant gas or the off-fuel gas in the condensed water tank 13 and the exhaust part 20 passes through the second condensed water tank 25 to the second drainage path. 27 is prevented from leaking out. Further, the second condensate water tank 25 has a first sealing pressure due to a water head difference corresponding to a vertical distance between the second drainage path 27 and the exhaust gas passage disposed in the second condensate water tank 25. It is comprised so that it may become larger than a pressure.

[Operation and effect of fuel cell system]
Next, the operation and effect of the fuel cell system 100 according to Embodiment 2 will be described.

As described above, when the exhaust unit 20 is blocked or is closed on the way to the block, the pressure in the first condensed water tank 24 and the second condensed water tank 25 connected to the exhaust unit 20 increases. Since the second condensate water tank 25 includes a water seal portion that seals water so that the exhaust gas from the exhaust portion 20 does not flow, the first condensate water does not flow out from the exhaust portion 20 and flows at a predetermined pressure. The exhaust gas communication portions of the tank 24 and the second condensed water tank 25 are balanced. At that time, the predetermined pressure is similarly applied to the supply path 12 arranged in the first condensed water tank 24. Therefore, the water in the supply path 12 arranged outside the casing 101 rises up in the vertical direction of the pressure difference between the predetermined pressure and the atmospheric pressure.

  In the fuel cell system 100 according to the second embodiment, even when the exhaust unit 20 is closed or closed halfway before closing, it corresponds to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12. The sealing pressure due to the water head difference is configured to be larger than a predetermined first pressure. Therefore, it is possible to prevent the off-oxidant gas or off-fuel gas of the fuel cell from leaking out of the fuel cell system 100 through the water supply port without exceeding the sealing pressure due to the water head difference in the supply path 12. Is possible.

(Embodiment 3)
In the third embodiment, the description will focus on the parts different from the first and second embodiments.

  A fuel cell system 100 according to Embodiment 3 of the present invention houses a gas supply device that supplies an oxidant gas or a fuel gas to the fuel cell 5, and at least the fuel cell 5, the condensed water tank 13, and the gas supply device. In addition, the casing 101 provided with the exhaust unit 20 and the condensed water tank 13 are formed between the first water storage unit 15 and the second water storage unit, and at the lower part of the condensed water tank 13, A second off-oxidant gas path 11 provided with a partition wall 14 so as to communicate with the second water storage unit, one end connected to the first water storage unit 15 of the condensed water tank 13 and the other end connected to the exhaust unit 20. And a water recovery tank 28 that stores the condensed water supplied from the exhaust part 20 and has a water seal part that seals water so that the exhaust from the exhaust part 20 does not flow. 28 through the first drainage path 22 The third drainage path 29 is connected to the condensed water tank 13 to discharge the water stored inside to the outside of the water recovery tank 28, and the upper end of the supply path 12 and the lower end of the supply path 12 are connected. The aspect which is comprised so that the sealing pressure by the water head difference equivalent to the distance of the vertical direction may become larger than the predetermined 1st pressure is illustrated.

Here, in Embodiment 3 , the gas supply device is the blower 6 that supplies the oxidant gas or the raw material supply unit 2, but in addition to this, the gas supply device of the fuel cell system 100 that supplies hydrogen directly to the fuel cell. In some cases, a device for supplying hydrogen may be used.

FIG. 5 is a schematic diagram showing a schematic configuration of the fuel cell system 100 according to Embodiment 3 of the present invention.

As shown in FIG. 5 , the fuel cell system 100 according to Embodiment 3 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 1, but the exhaust gas from the exhaust section 20 flows. The difference is that a water recovery tank 28 having a water seal portion for sealing with water is added.

  The water recovery tank 28 is configured to communicate the exhaust gas condensed water path 26 of the exhaust unit 20 and the first drainage path 22 of the condensed water tank 13, and collects water from the third drainage path 29 and the first drainage path 22. By performing gas-liquid separation in the tank 28, the off-oxidant gas or the off-fuel gas in the exhaust part 20 is prevented from leaking from the third drainage path 29 through the exhaust gas condensed water path 26. Further, the water recovery tank 28 has a sealing pressure due to a water head difference corresponding to the vertical distance between the second drainage path 27 and the exhaust gas passage disposed in the water recovery tank 28 larger than the first pressure. It is comprised so that it may become.

[Operation and effect of fuel cell system]
Next, the operation and effect of the fuel cell system 100 according to Embodiment 3 will be described.

  As described above, when the exhaust unit 20 is blocked or is closed on the way to the blockage, the pressure in the condensed water tank 13 and the water recovery tank 28 connected to the exhaust unit 20 increases to a predetermined pressure. . Since the water recovery tank 28 includes a water seal portion that seals water so that the exhaust from the exhaust portion 20 does not flow, the exhaust from the exhaust portion 20 does not flow, and the condensed water tank 13 is The exhaust gas communication part of the water recovery tank 28 is balanced. At that time, the predetermined pressure is applied to the supply path 12 arranged in the condensed water tank 13. Therefore, the water in the supply path 12 arranged outside the casing 101 rises up in the vertical direction of the pressure difference between the predetermined pressure and the atmospheric pressure.

  In the fuel cell system 100 according to the third embodiment, even when the exhaust unit 20 is blocked or closed in the middle of reaching the blockage, the water head difference corresponding to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12 Is configured to be larger than a predetermined first pressure. Therefore, it is possible to prevent the off-oxidant gas or off-fuel gas of the fuel cell from leaking out of the fuel cell system 100 through the water supply port without exceeding the sealing pressure due to the water head difference in the supply path 12. Is possible.

(Embodiment 4)
In the fourth embodiment, the description will be focused on the parts different from the first to third embodiments.

A fuel cell system 100 according to the fourth embodiment will be described with reference to FIG.

FIG. 6 is a schematic diagram showing a schematic configuration of the fuel cell system 100 of the fourth embodiment.

As shown in FIG. 6 , the fuel cell system 100 of the fourth embodiment has the same basic configuration as the fuel cell system 100 according to the second embodiment, but the first condensed water connected to the exhaust unit 20. A pressure detector 30 is further provided for detecting that the pressure of the first water storage section 15 of the tank 24 is equal to or higher than a predetermined second pressure, and the vertical direction between the upper end of the supply path 12 and the lower end of the supply path 12 The fuel cell system 100 is configured such that the sealing pressure due to the water head difference corresponding to the distance of is greater than a predetermined second pressure, and the pressure detected by the pressure detector 30 is higher than the second pressure. Is different in that it is configured to stop the operation.

  The pressure detected by the pressure detector 30 refers to the pressure applied to the first water storage unit 15 of the condensed water tank 13 connected to the exhaust unit 20 and is normally equal to the atmospheric pressure, but the exhaust unit 20 is blocked and When it is blocked halfway, a first pressure that is a supply pressure from the blower 6 and the raw material supply unit 2 is applied.

  Therefore, the “second pressure” is set to a pressure lower than the sealing pressure due to the water head difference corresponding to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12 that can be secured in the configuration of the fuel cell system 100. The

  Although the pressure detector 30 illustrated the aspect of the pressure switch which cut | disconnects an internal electric circuit and stops the fuel cell system 100 when the pressure to detect becomes 2nd pressure or more, it is not limited to this, A pressure gauge And a control unit that determines an abnormality based on a pressure value detected by a pressure gauge. Moreover, although the pressure detector 30 has illustrated the arrangement | positioning in the 1st condensed water tank 24 so that the pressure applied to the 1st water storage part 15 can be detected directly, if the pressure applied to the 1st water storage part 15 can be detected, For example, you may arrange | position in the exhaust part 20. FIG.

[Operation and effect of fuel cell system]
Next, the operation and effect of the fuel cell system 100 according to Embodiment 4 will be described.

  As described above, when the exhaust unit 20 is blocked or is closed on the way to the block, the pressure in the first condensed water tank 24 and the second condensed water tank 25 connected to the exhaust unit 20 increases. Since the second condensate water tank 25 includes a water seal portion that seals water so that the exhaust gas from the exhaust portion 20 does not flow, the first condensate water does not flow out from the exhaust portion 20 and flows at a predetermined pressure. The exhaust gas communication portions of the tank 24 and the second condensed water tank 25 are balanced. At that time, the predetermined pressure is applied to the supply path 12 arranged in the first condensed water tank 24. Therefore, the water in the supply path 12 arranged outside the casing 101 rises up in the vertical direction of the pressure difference between the predetermined pressure and the atmospheric pressure.

  In the fuel cell system 100 according to the fourth embodiment, even when the exhaust part 20 is blocked or closed in the middle of reaching the blockage, the water head difference corresponding to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12 Is configured to be larger than a predetermined second pressure. Further, the fuel cell system 100 is configured to stop when the pressure detected by the pressure detector 30 becomes higher than the second pressure. Therefore, it is possible to prevent the off-oxidant gas or off-fuel gas of the fuel cell from leaking out of the fuel cell system 100 through the water supply port without exceeding the sealing pressure due to the water head difference in the supply path 12. Is possible.

(Embodiment 5)
In the fifth embodiment, the description will be focused on the parts different from the first to fourth embodiments.

The fuel cell system 100 according to Embodiment 5 will be described with reference to FIG.

FIG. 7 is a schematic diagram showing a schematic configuration of the fuel cell system 100 of the fifth embodiment.

As shown in FIG. 7 , the fuel cell system 100 of the fifth embodiment has the same basic configuration as the fuel cell system 100 according to the third embodiment, but the condensed water tank 13 connected to the exhaust unit 20. And a pressure detector 30 for detecting that the pressure of the first water storage section 15 is equal to or higher than a predetermined second pressure, and a vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12. The fuel cell system 100 is stopped when the pressure detected by the pressure detector 30 becomes higher than the second pressure. The difference is that it is configured to operate.

  The pressure detected by the pressure detector 30 refers to the pressure applied to the first water storage unit 15 of the condensed water tank 13 connected to the exhaust unit 20 and is normally equal to the atmospheric pressure, but the exhaust unit 20 is blocked and When it is blocked halfway, a first pressure that is a supply pressure from the blower 6 and the raw material supply unit 2 is applied.

  Therefore, the “second pressure” is set to a pressure lower than the sealing pressure due to the water head difference corresponding to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12 that can be secured in the configuration of the fuel cell system 100. The

  Although the pressure detector 30 illustrated the aspect of the pressure switch which cut | disconnects an internal electric circuit and stops the fuel cell system 100 when the pressure to detect becomes 2nd pressure or more, it is not limited to this, A pressure gauge And a control unit that determines an abnormality based on a pressure value detected by a pressure gauge. Moreover, although the pressure detector 30 has illustrated arrangement | positioning in the condensed water tank 13 so that the pressure applied to the 1st water storage part 15 can be detected directly, if the pressure applied to the 1st water storage part 15 can be detected, it will exhaust, for example It may be arranged in the part 20.

[Operation and effect of fuel cell system]
Next, the operation and effect of the fuel cell system 100 according to Embodiment 5 will be described. As described above, when the exhaust unit 20 is closed or is closed on the way to the blockage, the pressure in the condensed water tank 13 and the water recovery tank 28 connected to the exhaust unit 20 increases. Since the water recovery tank 28 includes a water sealing portion that seals water so that the exhaust from the exhaust portion 20 does not flow, the exhaust from the exhaust portion 20 does not flow, and the condensed water tank 13 and the water can be The exhaust gas communication part of the recovery tank 28 is balanced. At that time, the predetermined pressure is applied to the supply path 12 arranged in the condensed water tank 13. Therefore, the water in the supply path 12 arranged outside the casing 101 rises up in the vertical direction of the pressure difference between the predetermined pressure and the atmospheric pressure.

  In the fuel cell system 100 according to Embodiment 5, even when the exhaust unit 20 is closed or closed halfway to the closed state, the water head difference corresponding to the vertical distance between the upper end of the supply path 12 and the lower end of the supply path 12 Is configured to be larger than a predetermined second pressure. Further, the fuel cell system 100 is configured to stop when the pressure detected by the pressure detector 30 becomes higher than the second pressure. Therefore, it is possible to prevent the off-oxidant gas or off-fuel gas of the fuel cell from leaking out of the fuel cell system 100 through the water supply port without exceeding the sealing pressure due to the water head difference in the supply path 12. Is possible.

  The exhaust path described in the claims includes the off fuel gas path 4b, the first off oxidant gas path 8, the off combustion gas path 9, the off combustion gas condensate water path 10, and the second off oxidant gas. It is at least one of the paths 11.

  The fuel cell system of the present invention is useful in the field of fuel cells because it can prevent the exhaust gas of the fuel cell from leaking out of the fuel cell system from the water supply port even if the water supply port is forgotten to close.

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Raw material supply part 3 Water supply part 4a Hydrogen supply path 4b Off fuel gas path 5 Fuel cell 6 Blower 7 Oxidant gas path 8 First off oxidant gas path 9 Off combustion gas path 10 Off combustion gas condensed water Path 11 Second off-oxidant gas path 12 Supply path 13 Condensed water tank 14 Bulkhead 15 First water storage section 16 Second water storage section 17 Water level sensor 18 Exhaust gas heat exchanger 19 Exhaust air heat exchanger 20 Exhaust section 21 Water supply port 22 First 1 drainage path 23 waste heat recovery water path 24 first condensed water tank 25 second condensed water tank 26 exhaust gas condensed water path 27 second drainage path 28 water recovery tank 29 third drainage path 30 pressure detector 31 water supply 32 water Purifier 33 Communication unit 34 Drain port 100 Fuel cell system 101 Case

Claims (8)

A fuel cell that generates power using oxidant gas and fuel gas;
A condensed water tank for storing condensed water generated by condensing water vapor contained in at least one of the off-oxidant gas or the off-fuel gas discharged from the fuel cell; and
A water supply port whose upper end is arranged vertically above the condensed water tank, and a supply path for supplying purified water from the water supply port to the condensed water tank;
In a fuel cell system comprising:
An exhaust path for discharging the off gas to the outside of the fuel cell system;
The condensed water tank includes a first water storage unit to which the condensed water is supplied,
The lower end of the supply path connected to the condensate tank is disposed in the first water reservoir below the first water level that is set in advance so as to reach when water is supplied by manual water supply. It is comprised so that the sealing pressure by the hydraulic head difference corresponding to the distance of the perpendicular direction of the uppermost part of the said supply path | route and the lower end of the said supply path | route may become larger than the predetermined 1st pressure. Characterized by
Fuel cell system. A water level sensor for detecting the water level in the condensed water tank;
The lower end of the supply path connected to the condensed water tank is configured to be arranged below the second water level detected by the water level sensor in the vertical direction.
The fuel cell system according to claim 1.   3. The fuel cell system according to claim 2, wherein the fuel cell system is configured to stop when a water level detected by the water level sensor becomes lower than the second water level. 4. A drainage port connected to the drainage port of the condensed water tank, further comprising a first drainage path for discharging water stored in the first water storage unit to at least the outside of the first water storage unit;
The condensed water tank further includes a second water storage unit that is in communication with the first water storage unit and configured to seal the gas of the first water storage unit,
The lower end of the supply path connected to the condensed water tank is configured to be arranged in the first water storage section below the drain port in the vertical direction.
The fuel cell system according to any one of claims 1 to 3. A gas supplier for supplying an oxidant gas or a fuel gas to the fuel cell;
A housing in which at least the fuel cell, the condensed water tank, and the gas supplier are housed, and an exhaust part for exhausting the off-gas is formed,
Further comprising
The exhaust path has one end connected to the first water storage part of the condensed water tank and the other end connected to the exhaust part.
The condensed water tank includes a first condensed water tank provided with the first water storage section, and a first for discharging water stored inside the first water storage section to at least the outside of the first water storage section. A second condensed water tank that communicates with the first condensed water tank through a drainage path and includes a second water storage section;
The second condensed water tank stores condensed water supplied from the exhaust part, and includes a water seal part that seals water so that exhaust gas from the exhaust part is not exhausted.
The second drainage path for discharging the water stored inside the second water reservoir to the outside of the second water reservoir is connected to the second condensate tank,
The fuel cell system according to any one of claims 1 to 3. A gas supplier for supplying an oxidant gas or a fuel gas to the fuel cell;
A housing in which at least the fuel cell, the condensed water tank, and the gas supplier are housed, and an exhaust part for exhausting the off-gas is formed,
A water recovery tank that has a water seal portion that stores condensed water supplied from the exhaust portion and seals water so that exhaust from the exhaust portion does not flow,
Further comprising
The condensed water tank is formed in the condensed water tank with a second water storage part formed across the first water storage part and a partition wall, and the first water storage part and the lower part of the condensed water tank. A communication part configured to communicate with the second water storage part,
The exhaust path has one end connected to the condensed water tank and the other end connected to the exhaust part,
The water recovery tank communicates with the condensed water tank via a first drainage path, and a third drainage path for discharging water stored inside to the outside of the water recovery tank is connected. Characterized by
The fuel cell system according to any one of claims 1 to 3. A pressure detector for detecting that the pressure of the first water storage section of the condensed water tank is equal to or higher than a predetermined second pressure;
The sealing pressure due to the water head difference corresponding to the vertical distance between the uppermost part of the supply path and the lower end of the supply path is configured to be larger than the second pressure,
The fuel cell system according to any one of claims 1 to 6. The pressure detected by the pressure detector is configured to stop the fuel cell system when the pressure becomes higher than the second pressure.
The fuel cell system according to claim 7.