JP2015113987A - Power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sticking of a backflow prevention device and deterioration of a ventilation fan caused by rust due to adhesion of condensate water in a combustion exhaust gas.SOLUTION: A power generation system includes: a confluence path 70 connected to external piping; a ventilation path 75 connected to a first connection part 89 of the confluence path 70, and exhausting a ventilation gas; an exhaust path 77 connected to a second connection part 90 located on a further downstream than the first connection part 89 of the confluence path 70, and exhausting an exhaust gas; and a backflow prevention device 20 provided at the ventilation path 75. The first connection part 89 and the second connection part 90 are arranged vertically upward. Then, out of the ventilation path 75, a flow passage which is further downstream than the backflow prevention device 20 is configured to suppress a fluid flowing from the downstream side to the upstream side. Thereby, condensate water generated in the exhaust path 77 and the confluence path 70 can be prevented from adhering to the backflow prevention device 20 and a ventilation fan 13 connected to the uppermost stream of the ventilation path 75, so that sticking of the backflow prevention device 20 and deterioration of the ventilation fan 13 caused by rust can be prevented.

Description

  The present invention relates to a fuel cell system that supplies heat and electricity.

  A fuel cell supplies hydrogen or a hydrogen-rich gas to one of the electrodes sandwiching the electrolyte (hereinafter, the one that supplies the hydrogen-rich gas is referred to as the “anode side”), and the other is supplied with an oxidant gas such as oxygen-containing air. The power is supplied (hereinafter, the direction in which the oxidant gas is supplied is referred to as “cathode side”), and power is generated by an electrochemical reaction.

  A fuel cell system is a cogeneration system that supplies electric power generated by a fuel cell to a consumer to cover an electric power load, and recovers exhaust heat generated by the electric power generation and stores it to cover a hot water supply load of the consumer.

  As such a fuel cell system, air used in the fuel cell system is supplied from outside the building through an air supply path connected to the fuel cell system, and exhaust connected to the fuel cell system. 2. Description of the Related Art A fuel cell system that exhausts exhaust gas generated in a fuel cell system to the outside of a building via a route is known (see, for example, Patent Documents 1-3).

  The fuel cell system disclosed in Patent Document 1 is connected to an exhaust pipe for discharging exhaust gas generated in the fuel cell, and this exhaust pipe is connected to a lower part of a duct extending in the vertical direction leading to the outdoors. Has been.

  FIG. 4 is a configuration diagram of the fuel cell system disclosed in Patent Document 1. As shown in FIG. As shown in FIG. 4, in the fuel cell system disclosed in Patent Document 1, a fuel cell 131 is housed in a building consisting of a house, and the fuel cell 131 generates in the fuel cell 131. An exhaust pipe 133 for discharging exhaust gas is connected, and this exhaust pipe 133 is arranged vertically in the building, in other words, connected to the lower part of the duct 135 extending in the vertical direction (height direction). ing. The fuel cell 131 is housed in an upper room that is partitioned vertically by a partition plate 139 inside the outer container 137, and an auxiliary machine (not shown) of the fuel cell 131 is housed in the lower room of the outer container 137. Yes. The fuel cell 131 is configured by housing a cell stack in which a plurality of fuel cells are assembled and a reformer (not shown) in a storage container, and supplying fuel gas and oxygen-containing gas to the fuel cells. Then, power generation is performed by an electrochemical reaction, and surplus fuel gas and oxygen-containing gas are discharged from the exhaust pipe 133 and the duct 135 as exhaust gas. The duct 135 is disposed in the building in the height direction, and a lower end portion thereof is located inside the building and extends upward, and an upper end portion thereof penetrates the roof and is located outside the building. In such a power generator, since the lower end of the duct 135 extending in the vertical direction is located in the building and the upper end is located outside the building, the temperature of the lower end of the duct 135 is higher than the upper end, When the exhaust pipe 133 is connected to the lower end of the duct 135 and the exhaust gas of the fuel cell 131 is introduced into the lower end of the duct 135, the exhaust gas is heated at the lower end of the duct 135 due to the high exhaust gas temperature. The exhaust gas becomes lighter and rises, so that the duct 135 is raised by a so-called chimney effect, the exhaust gas is discharged upward, and the exhaust performance can be improved.

  The fuel cell system disclosed in Patent Document 2 is provided with a water tank that stores condensed water generated by cooling while exhaust gas containing water vapor discharged from the fuel cell system flows through the exhaust path. .

FIG. 5 is a configuration diagram of the fuel cell system disclosed in Patent Document 2. As shown in FIG. As shown in FIG. 5, the intake / exhaust device of the fuel cell system disclosed in Patent Document 2 includes a double pipe duct 31 attached to the upper portion of the main body 30 by a duct connection portion 32, a system air duct 34, It has a ventilation descending duct 35 and a mixing box 37 to which an exhaust fan 36 is attached.

  The double pipe duct 31 forms an annular intake / exhaust flow path by the inner pipe 31a and the outer pipe 31b. Air 40 (fresh outdoor air) introduced from the outer pipe 31 b of the double pipe duct 31 is branched inside the main body 30 by the system air duct 34 and the ventilation descending duct 35.

  The system exhaust 45 exhausted from the fuel processing device of the main body 30 and the fuel cell main body contains a large amount of water vapor. In the mixing box 37, the water vapor partial pressure contained in the system exhaust 45 is reduced by mixing with the ventilation 46 sent out by the ventilation fan 36. However, when the temperature of the ventilation 46 is low, the water vapor is condensed and accumulated in the lower portion of the mixing box 37.

  On the other hand, the mixed exhaust 47 flowing through the inner pipe 31a of the double pipe duct 31 is cooled by the air sucked through the inner wall of the inner pipe 31a, so that water vapor is condensed on the wall surface. The moisture condensed on the wall surface of the inner pipe 31 a flows down toward the mixing box 37 due to the gradient of the duct 31.

  Therefore, all the condensed water (condensed water) is collected in the mixing box 37 and further stored in the water tank 51 as a water storage section through the drain pipe 50. The condensed water collected in the water tank 51 can also be used for power generation in the power generation body 30. When unnecessary, the water tank 51 is configured to drain from the upper seat to the outside of the main body 30 through a drainage path (not shown).

  In the fuel cell system disclosed in Patent Document 3, a backflow prevention device is provided in the discharge path. FIG. 6 is a configuration diagram of the fuel cell system disclosed in Patent Document 3. As shown in FIG. As shown in FIG. 6, the fuel cell system disclosed in Patent Document 3 includes a fuel cell system 101 having a fuel cell 11, a casing 12, a reformer 14a, and a combustor 14b, and a ventilation fan (ventilator). ) 13, a controller 102, a combustion device 103, a discharge flow path 70, and a backflow prevention device 20. The exhaust passage 70 is provided so as to communicate the housing 12 of the fuel cell system 101 and the exhaust port 103A of the combustion device 103. In the housing 12 of the fuel cell system 101, a fuel cell 11, a ventilation fan 13, a fuel gas supply device 14, and an oxidant gas supply device 15 are arranged. The controller 102 is also disposed in the housing 12.

  A hole 16 penetrating in the thickness direction of the wall is provided at an appropriate position of the wall constituting the housing 12, and the pipe constituting the discharge flow path 70 has a gap in the hole 16, It is inserted. The gap between the hole 16 and the discharge flow path 70 constitutes the air supply port 16. Thereby, air outside the power generation system 100 is supplied into the housing 12 through the air supply port 16.

  The upstream end of the off-fuel gas channel 73 is connected to the outlet of the fuel gas channel 11A. The downstream end of the off fuel gas channel 73 is connected to the discharge channel 70. The upstream end of the off-oxidant gas channel 74 is connected to the outlet of the oxidant gas channel 11B. The downstream end of the off-oxidant gas channel 74 is connected to the discharge channel 70.

  The ventilation fan 13 is connected to the discharge flow path 70 via the ventilation path 75. As a result, air outside the power generation system 100 is supplied into the housing 12 from the air supply port 16, and the ventilation fan 13 is operated, whereby the gas (mainly air) in the housing 12 is exhausted from the ventilation path 75 and the exhaust air. It is discharged out of the building 200 through the flow path 70, and the inside of the housing 12 is ventilated.

  The combustion device 103 includes a combustor 17 and a combustion fan (combustion air supply device) 18. The combustor 17 and the combustion fan 18 are connected via a combustion air supply passage 76.

  Combustion fuel such as combustible gas such as natural gas or liquid fuel such as kerosene is supplied to the combustor 17 from a combustion fuel supply unit (not shown). In the combustor 17, the combustion air supplied from the combustion fan 18 and the combustion fuel supplied from the combustion fuel supplier are burned to generate heat, and combustion exhaust gas is generated.

  An upstream end of the exhaust gas passage 77 is connected to the combustor 17, and a downstream end of the exhaust gas passage 77 is connected to the exhaust passage 70. Thereby, the combustion exhaust gas generated by the combustor 17 is discharged to the discharge passage 70 via the exhaust gas passage 77. That is, the combustion exhaust gas generated by the combustor 17 is discharged to the discharge passage 70 as the exhaust gas discharged from the combustion device 103. The combustion exhaust gas discharged to the discharge flow path 70 flows through the discharge flow path 70 and is discharged outside the building 200.

  A hole 19 penetrating in the thickness direction of the wall is provided at an appropriate position of the wall constituting the combustion device 103, and the pipe constituting the discharge flow path 70 has a gap in the hole 19, It is inserted. The gap between the hole 19 and the discharge channel 70 constitutes the air supply port 19. Thereby, the air outside the power generation system 100 is supplied into the combustion device 103 through the air supply port 19.

  A backflow prevention device 20 is provided between the upstream end of the discharge flow path 70 on the hole 16 side and the branch point of the discharge flow path 70. Here, the backflow prevention device 20 is configured by a ball check valve, and includes a ball (valve element) 20a and a valve seat 20b.

JP 2008-210631 A JP 2006-253020 A International Publication No. 12/153482

  However, in any of the configurations of the fuel cell systems disclosed in Patent Documents 1 to 3, the water vapor contained in the exhaust is cooled and condensed by the combination of ventilation and exhaust, and the condensed water flows backward in the ventilation path. As a result, the backflow prevention device or the ventilation fan may come into contact with the backflow prevention device or the ventilation fan may be deteriorated. This is a problem that cannot be solved even in the combination of Patent Documents 1-3.

  The present invention solves the above-described conventional problems, and has a merging path connected to a duct connected to the outdoors, and a merging path to which an exhaust path for exhausting ventilation gas containing air is connected. The connecting portion and a second connecting portion that exhausts the exhaust gas containing water vapor are connected, the second connecting portion is connected downstream of the first connecting portion of the merging path, and the first connecting portion and the second of the merging path. The structure is arranged vertically upward from the upstream to the downstream, and the backflow prevention device and the ventilation device are arranged in the ventilation path, and the backflow prevention device is arranged downstream of the ventilation device. As a result, the water vapor contained in the exhaust is cooled and condensed by the combination of the ventilation and the exhaust, and the condensed water flows backward in the ventilation path and contacts the backflow prevention device or the ventilation fan. The ventilation fan will deteriorate. And an object thereof is to provide a fuel cell system that can prevent.

  In order to solve the above-described conventional problems, a fuel cell system according to the present invention includes a power generator that generates power using raw fuel, a merging path that is connected to the outside, and a first connection portion at one end of the merging path. And a ventilation path for exhausting the ventilation gas containing air, and one end connected to a second connection part located on the downstream side of the ventilation gas with respect to the first connection part of the merging path, An exhaust path for exhausting exhaust gas discharged from the generator, a backflow prevention device for preventing backflow of the ventilation gas provided in the ventilation path, and an upstream side of the backflow prevention apparatus in the ventilation path. Ventilation equipment. And the path | route between the said 1st connection part and the said 2nd connection part among the said confluence | merging path | routes is the structure inclined from the upstream to the downstream of the said ventilation gas, or the structure arrange | positioned vertically upwards The path downstream of the backflow prevention device in the ventilation path has a specific structure that suppresses the flow of liquid from the downstream side to the upstream side of the ventilation path.

  As a result, if incomplete combustion occurs in the generator, flammable gas may be contained in the exhaust path. However, if leakage occurs in the external piping connected to the outside at this time, the flammable gas leaks. There is a risk of taking out. Therefore, the combustible gas can be diluted by joining the combustion exhaust gas to the ventilation gas containing air in the joining path located upstream from the external pipe, so that safety can be improved. Also, by introducing ventilation gas first in the merging path and merging the combustion exhaust gas downstream of the ventilation gas, it is possible to reduce the contact of the flue gas containing moisture with the backflow prevention device provided in the ventilation path. The prevention device can be prevented from sticking. Furthermore, by providing a backflow prevention device in the ventilation path, it is possible to prevent the flue gas containing moisture from coming into contact with the ventilation fan, so that deterioration of the ventilation fan due to rust can be prevented. In addition, even when condensed water generated by condensation in the exhaust path flows into the merged part connected to the ventilation path, the flow path from the first connection part, which is the connection point between the merged path and the ventilation path, to the backflow prevention device Suppresses the flow of fluid from the downstream side to the upstream side, thus preventing condensed water from adhering to the backflow prevention device and the ventilation fan, thus preventing the backflow prevention device from sticking and deterioration of the ventilation fan due to rust. .

  According to the fuel cell system of the present invention, the water vapor contained in the exhaust is cooled and condensed by the combination of ventilation and exhaust, and the condensed water flows backward through the ventilation path and contacts the backflow prevention device or the ventilation fan. It is possible to prevent the backflow prevention device from being stuck and the ventilation fan from being deteriorated by rust.

1 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention. Schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention. Schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention. Schematic diagram showing a schematic configuration of a conventional (Patent Document 1) fuel cell system Schematic diagram showing the schematic configuration of a conventional (Patent Document 2) fuel cell system Schematic diagram showing the schematic configuration of a conventional (Patent Document 3) fuel cell system

According to a first aspect of the present invention, a generator that generates power using raw fuel, a merging path that is connected to the outside, and a ventilator that has one end connected to the first connection part of the merging path and exhausts ventilation gas containing air. An exhaust path for exhausting exhaust gas containing water vapor and exhausted from the power generator, one end of which is connected to a second connection part positioned at a downstream side of the ventilation gas with respect to the first connection part of the merging path And a backflow prevention device that is provided in the ventilation path and prevents a backflow of the ventilation gas, and a ventilation device that is disposed upstream of the backflow prevention device in the ventilation path. And the path | route between the said 1st connection part and the said 2nd connection part among the said confluence | merging path | routes is the structure inclined from the upstream to the downstream of the said ventilation gas, or the structure arrange | positioned vertically upwards The path downstream of the backflow prevention device in the ventilation path has a specific structure that suppresses the flow of liquid from the downstream side to the upstream side of the ventilation path.

  As a result, the water vapor contained in the exhaust is cooled and condensed by the combination of the ventilation and the exhaust, and the condensed water flows backward in the ventilation path and contacts the backflow prevention device or the ventilation fan, and the backflow prevention device is fixed or ventilated. It can prevent the fan from deteriorating due to rust.

According to a second aspect of the present invention, in particular, in the fuel cell system according to the first aspect of the present invention, a drainage path further connected to a third connection portion at a lower portion of the merging path and draining condensed water in the merging path to the outside. As a result, even if a large amount of condensed water is generated in the merging path or rainwater enters, it can be drained outside without overflowing the merging path or ventilation path. Deterioration due to adhesion and rusting of ventilation fan can be prevented. Here, as a case where a large amount of condensed water is generated in the merging path, a case where a combustion device such as a boiler is connected to an external pipe connected to the merging path is assumed. Furthermore, since the external piping connected to the merging path extends outdoors, rainwater can actually flow in.
According to a third invention, in the fuel cell system according to any one of the first and second inventions, the path is inclined with respect to a horizontal plane or has a step in the path. Even when condensate produced by condensation in the exhaust path flows into the junction where the ventilation path is connected, the flow path from the first connection portion, which is the connection point between the junction path and the ventilation path, to the backflow prevention device is Since the flow of fluid from the downstream side to the upstream side is suppressed, the condensed water can be prevented from adhering to the backflow prevention device and the ventilation fan, so that the backflow prevention device can be prevented from being stuck and the ventilation fan from being deteriorated by rust.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 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)
First, the configuration of the fuel cell system according to Embodiment 1 of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the fuel cell system 100 according to the first embodiment is arranged inside a building 200. The fuel cell system 100 includes a fuel processor 14, an oxidant gas supplier 15, a fuel cell 11, a ventilation fan 13, and a control device 102 in a housing 12. The fuel cell system 100 includes a supply / exhaust mechanism 104 having a merging path 70, and the supply / exhaust mechanism 104 is connected to an external pipe 76 that is open to the outdoors.

The control device 102 may be in any form as long as it is a device that controls each device constituting the fuel cell system 100. The control device 102 includes an arithmetic processing unit exemplified by a microprocessor, a CPU, and the like, and a storage unit configured by a memory that stores a program for executing each control operation. Then, in the control device 102, the arithmetic processing unit reads out a predetermined control program stored in the storage unit and executes it, thereby processing the information and the fuel cell system 100 including these controls. Various controls are performed. The control device 102 is not only configured as a single control device, but also configured as a controller group in which a plurality of control devices cooperate to execute control of the fuel cell system 100. I do not care. Moreover, the control apparatus 102 may be comprised with the microcomputer, and may be comprised by MPU, PLC (programmable logic controller), a logic circuit, etc.

  A hole 16 penetrating in the thickness direction of the wall is provided at an appropriate position of the wall constituting the housing 12, and the air supply / exhaust mechanism 104 protrudes from the hole 16 to the outside of the fuel cell system 100. The end of the air supply / exhaust mechanism 104 is connected to an external pipe 76 that is open to the outdoors. In the present embodiment, the pipe constituting the merging path 70 is a double pipe arranged inside the pipe constituting the air supply flow path 78, but the ventilation path 75 inside the fuel cell system 100 is used. As long as the exhaust path 77 is connected to the external pipe 76, it is not always necessary to have a double pipe structure. Since the downstream end of the external pipe 76 is open to the outdoors, air can be supplied to the fuel cell system 100 from the outside (here, outside the building 200).

  The fuel cell 11 has an anode and a cathode (both not shown). In the fuel cell 11, the fuel gas supplied to the fuel gas channel 11A is supplied to the anode while flowing through the fuel gas channel 11A. Further, the oxidant gas supplied to the oxidant gas flow channel 11B is supplied to the cathode while flowing through the oxidant gas flow channel 11B. The fuel gas supplied to the anode and the oxidant gas supplied to the cathode react to generate electricity and heat.

  Here, 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 a heat medium flowing through a heat medium flow path (not shown). The heat recovered by the heat medium can be used, for example, to heat water. In the first embodiment, the fuel cell 11 can use various fuel cells such as a polymer electrolyte fuel cell and a solid oxide fuel cell. Furthermore, since the structure of the fuel cell 11 is the same as that of a general fuel cell, its detailed description is omitted.

  The upstream end of the off-fuel gas channel 73 is connected to the outlet of the fuel gas channel 11A. The downstream end of the off fuel gas flow path 73 is connected to a combustor 14b described later. A fuel gas containing hydrogen that has not been used in the fuel cell 11 (hereinafter, “off fuel gas”) is supplied to the combustor 14 b via the off fuel gas passage 73.

  The upstream end of the off-oxidant gas channel 74 is connected to the outlet of the oxidant gas channel 11B. The downstream end of the off-oxidant gas channel 74 is connected to a second connection part 90 described later. The oxidant gas (hereinafter referred to as off-oxidant gas) that has not been used in the fuel cell 11 flows from the outlet of the oxidant gas flow path 11B to the off-oxidant gas flow path 74, the exhaust path 77, the second connecting portion 90, and the merge path. 70 and the outside pipe 76 to be discharged outside the building 200.

  The fuel processor 14 supplies a fuel gas (gas containing hydrogen) to the fuel cell 11 while adjusting the flow rate thereof, and includes a reformer 14a, a combustor 14b, and a combustion fan 14c. The fuel processor 14 is connected to the fuel cell 11 (more precisely, the inlet of the fuel gas channel 11 </ b> A of the fuel cell 11) via the fuel gas supply channel 71.

  The reformer 14a is connected to a raw material supply device and a steam supply device (not shown respectively), and the raw material and water vapor are supplied to the reformer 14a, respectively. As the raw material, natural gas mainly composed of methane, LP gas, or the like can be used.

Further, the reformer 14a has a reforming catalyst. As the reforming catalyst, any substance may be used as long as it can catalyze a steam reforming reaction that generates a hydrogen-containing gas from a raw material and steam, for example, ruthenium on a catalyst carrier such as alumina. A ruthenium catalyst supporting (Ru) or a nickel catalyst supporting nickel (Ni) on the same catalyst carrier can be used.

  In the reformer 14a, a hydrogen-containing gas is generated by a reforming reaction between the supplied raw material and water vapor. The generated hydrogen-containing gas flows as a fuel gas through the fuel gas supply channel 71 and is supplied to the fuel gas channel 11 </ b> A of the fuel cell 11. In the first embodiment, the hydrogen-containing gas generated in the reformer 14a is sent to the fuel cell 11 as fuel gas. However, the present invention is not limited to this. A shifter having a shift catalyst (for example, a copper-zinc based catalyst) for reducing carbon monoxide in the hydrogen-containing gas sent from the reformer 14a, an oxidation catalyst (for example, a ruthenium based catalyst), The configuration may be such that the hydrogen-containing gas after passing through a carbon monoxide remover having a methanation catalyst (for example, a ruthenium-based catalyst) is sent to the fuel cell 11.

  The combustor 14 b is connected to the downstream end of the off-fuel gas passage 73, and off-fuel gas from the fuel cell 11 flows through the off-fuel gas passage 73 and is supplied as combustion gas. A combustion fan 14 c is connected to the combustor 14 b via a combustion air supply flow path 79. The combustion fan 14c may have any configuration as long as it can supply combustion air to the combustor 14b. For example, the combustion fan 14c may be configured by fans such as a fan and a blower.

  In the combustor 14b, the supplied off-fuel gas and combustion air are combusted to generate heat, and combustion exhaust gas is generated. The combustion exhaust gas generated by the combustor 14 b is discharged to the combustion exhaust gas flow path 80 after heating the reformer 14 a and the like. The combustion exhaust gas discharged to the combustion exhaust gas flow path 80 flows through the combustion exhaust gas flow path 80 and is discharged outside the building 200 through the exhaust path 77, the second connection portion 90, the merge path 70, and the external pipe 76. In the first embodiment, the combustor 14b is configured so that off-fuel gas is supplied from the fuel cell 11 as the combustion gas. However, the present invention is not limited to this, and the combustion gas supply device is connected to the combustor 14b. Alternatively, the combustion gas may be separately supplied.

  The oxidant gas supply unit 15 may have any configuration as long as the oxidant gas (air) can be supplied to the fuel cell 11 while adjusting the flow rate thereof. For example, fans such as fans and blowers It may be comprised. The oxidant gas supply unit 15 is connected to the fuel cell 11 (more precisely, the inlet of the oxidant gas channel 11B of the fuel cell 11) via the oxidant gas supply channel 72.

  The ventilation fan 13 is connected to the merging path 70 via the ventilation path 75 at the first connecting portion 89, and the exhaust path 77 is merged at the second connecting portion 90 on the downstream side of the merging path 70. ing. The ventilation fan 13 may have any configuration as long as the inside of the housing 12 can be ventilated. As a result, air outside the fuel cell system 100 is supplied from the air supply passage 78 into the housing 12, and the ventilation fan 13 is operated, whereby the gas (mainly air) in the housing 12 is supplied to the ventilation path 75 and It is discharged out of the building 200 through the first connection portion 89, the junction path 70, and the external piping 76, and the inside of the housing 12 is ventilated. In the first embodiment, a fan is used as a ventilator. However, the present invention is not limited to this, and a blower may be used. The ventilation fan 13 is configured to be disposed in the housing 12, but is not limited thereto. The ventilation fan 13 may be arranged in the first exhaust path 77.

  A backflow prevention device 20 is provided between the ventilation fan 13 and the ventilation path 75. The backflow prevention device 20 is configured by a swing type check valve, and fulfills a backflow prevention function by opening and closing a plate-shaped flap (valve element). Here, the backflow prevention device 20 is constituted by a swing type check valve, but is not limited to this, and various check valves such as a lift type check valve, a ball type check valve and a diaphragm type check valve are used. It can consist of valves.

  As described above, in the first embodiment, the gas (air) supplied to the casing 12 by the operation of the combustion fan 14c, the oxidant gas supplier 15, and the ventilation fan 13 is supplied to the fuel cell system 100. It is illustrated as the external air supplied. The outside air supplied to the fuel cell system is not limited to these gases (air). For example, in the case where the fuel processor includes a selective oxidizer, it may be selectively oxidized air. Alternatively, bleed air supplied to the anode of the fuel cell 11 to prevent poisoning of the catalyst by carbon monoxide may be used.

  In the first embodiment, the combustion exhaust gas, the off-oxidant gas, and the gas in the housing 12 due to the operation of the ventilation fan 13 are exemplified as the exhaust gas discharged from the fuel cell system 100. . These exhaust gases are mixed at the first connection portion 89 and the second connection portion 90 of the merging path 70 in the housing 12, and then discharged to the outside via the external piping 76 outside the fuel cell system 100.

  Further, a first water recovery unit 85 is provided below the combustion exhaust gas channel 80, and the combustion exhaust gas channel 80 and the first water recovery unit 85 are connected by a first condensed water channel 86.

  The flue gas flow path 80 is inclined such that the condensed water generated when the temperature of the exhaust gas decreases in the flue gas flow path 80 flows into the first water recovery unit 85 via the first condensed water path 86. The shape and the connection position of the off-oxidant gas passage 74, the combustion exhaust gas passage 80, the exhaust passage 77, and the first condensed water passage 86 are taken into consideration.

  About the fuel cell system comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. Note that the start-up operation, power generation operation, and stop operation of the fuel cell system 100 are performed in the same manner as a general fuel cell system, and thus detailed description thereof is omitted. Further, in the first embodiment, description will be made assuming that the control device 102 controls each device constituting the fuel cell system 100.

  During the power generation operation of the fuel cell system 100, the fuel gas generated by the fuel processor 14 is supplied to the fuel cell 11, and the oxidant gas is supplied by the oxidant gas supply unit 15. The off-oxidant gas in which a part of oxygen is used for power generation in the fuel cell 11 and the oxygen concentration is lowered is discharged from the outlet of the oxidant gas channel 11B to the off-oxidant gas channel 74.

  Further, the off-fuel gas containing hydrogen that has not been used in the fuel cell 11 is supplied to the combustor 14b and burned together with the combustion air supplied by the combustion fan 14c. The combustion exhaust gas having a low oxygen concentration generated by the combustion in the combustor 14b is heated to the reformer 14a and then discharged to the combustion exhaust gas flow path 80.

Further, during the power generation operation of the fuel cell system 100, the ventilation fan 13 is driven, and the gas (air) in the housing 12 is discharged to the ventilation path 75.
The flue gas discharged to the flue gas flow path 80 is connected to the merging path 70 at the second connecting portion 90, and the gas (air) in the housing 12 discharged to the ventilation path 75 is connected to the first connecting portion 89. It is connected to the merge path 70. At this time, since the second connecting portion 90 is located downstream of the first connecting portion 89 in the merge path 70, the combustion exhaust gas is always diluted with air in the flow path downstream of the second connecting portion 90. It will be. If incomplete combustion occurs in the combustor 14b, there is a possibility that combustible gas may be contained in the combustion exhaust gas flow path 80. However, since it is diluted in the second connection portion 90, downstream of the exhaust of the fuel cell system 100 The diluted combustible gas can always flow from the exhaust path of the air supply / exhaust mechanism 104 at the end, so that even if leakage occurs in the external pipe 76, it is not unsafe, so the fuel cell system 100 Can improve safety.
During the power generation operation of the fuel cell system 100, the off-oxidant gas, the combustion exhaust gas, and the gas (air) in the housing 12 due to the operation of the ventilation fan 13 are mixed in the merging path 70 as exhaust gas, and the outside It is discharged to the outside through the pipe 76.

  Further, by providing the backflow prevention device 20 between the ventilation fan 13 and the ventilation path 75, the fuel cell system 100 is stopped and discharged from a combustion device (not shown) linked to the external pipe 76. When the exhausted combustion exhaust gas flows back through the joining path 70, the internal pressure of the joining path 70 increases, and pressure is applied in the direction in which the plate-like flap (valve body) of the backflow prevention device 20 is closed, thereby preventing backflow. Is done. On the other hand, when the internal pressure of the exhaust gas discharged from the fuel cell system 100 and / or the ventilation fan 13 increases due to the operation of the fuel cell system 100 and / or the ventilation fan 13, the flap (valve element) opens, Exhaust gas can flow through the ventilation path 75.

  Further, the ventilation gas is introduced into the upstream first connection portion 89 in the merging path 70 and the combustion exhaust gas is merged in the downstream side of the ventilation gas, that is, the second connection portion 90, so that the ventilation path 75 and the ventilation fan 13 are connected. Since it is possible to reduce the contact of the flue gas containing moisture with the backflow prevention device 20 provided therebetween, the backflow prevention device 20 can be prevented from sticking. Moreover, since the backflow prevention device 20 provided between the ventilation path 75 and the ventilation fan 13 can prevent the combustion exhaust gas containing moisture from coming into contact with the ventilation fan 13, deterioration of the ventilation fan 13 due to rust can be prevented. Even when condensed water generated by condensation in the exhaust path 77 flows into the ventilation path 75 via the merging path 70, it passes from the first connection portion 89, which is a connection point between the merging path 70 and the ventilation path 75, to the backflow prevention device 20. Since the flow path of the fluid suppresses the flow of fluid from the downstream side to the upstream side, it is possible to prevent the condensed water from adhering to the backflow prevention device 20 and the ventilation fan 13. Deterioration due to rust can be prevented.

  In general, the off-oxidant gas and the combustion exhaust gas discharged from the fuel cell system 100 are high in temperature and contain a lot of water vapor. Therefore, in order to recover and effectively use the heat of the off-oxidant gas and the combustion exhaust gas, the off-oxidant gas and the combustion exhaust gas include a heat medium that flows through a heat medium passage (not shown), and an off-oxidant. A heat exchange may be performed via a heat exchanger (not shown) provided in the middle of the gas flow path 74 and the combustion exhaust gas flow path 80 and then discharged to the merging path 70. Further, the condensed water generated by cooling the off-oxidant gas and the combustion exhaust gas in the heat exchanger (not shown) is recovered to the first water recovery unit 85 via the first condensed water path 86, and the fuel You may utilize for the reforming reaction which produces | generates fuel gas from a raw material with the modifier 14a of the processor 14. FIG.

In the fuel cell system 100 configured as described above, the off-oxidant gas and the combustion exhaust gas that have exited the heat exchanger (not shown) pass through the exhaust path 77, the merge path 70, and the external pipe 76 to the building 200. It is cooled before being discharged to the outside, and condensed water is generated.
In addition, the fuel cell system 100 of the present invention may further include a water use path for using the condensed water of the first water recovery unit 85 for operation of the fuel cell system 100 in the housing. The water utilization path may be, for example, a cooling water path for using the condensed water of the first water recovery unit as the cooling water used for heat recovery of the fuel cell 11. In addition, the water utilization path may be, for example, a reforming water path for using the condensed water of the first water recovery unit 85 as reforming water for reforming hydrocarbons.
In the present embodiment, the fuel processor 14 having the reformer 14a, the combustor 14b, and the combustion fan 14c is used as a device for supplying the fuel gas (gas containing hydrogen) to the fuel cell 11. For example, a hydrogen-containing gas supply device that directly supplies the hydrogen-containing gas to the fuel cell 11 using a hydrogen cylinder or the like may be used.

As described above, in the fuel cell system shown in the first embodiment, ventilation gas is introduced into the first connection portion 89 on the upstream side in the merge path 70, and the downstream side of the ventilation gas, that is, the second connection portion 9.
By combining the combustion exhaust gas at 0, it is possible to reduce the contact of the combustion exhaust gas containing moisture with the backflow prevention device 20 provided between the ventilation path 75 and the ventilation fan 13, so that the backflow prevention device 20 is prevented from sticking. I can do it. Moreover, since the backflow prevention device 20 provided between the ventilation path 75 and the ventilation fan 13 can prevent the combustion exhaust gas containing moisture from coming into contact with the ventilation fan 13, deterioration of the ventilation fan 13 due to rust can be prevented.

(Embodiment 2)
FIG. 2 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention. The same constituent elements as those in the first embodiment are denoted by the same reference numerals as those in FIG.

  As shown in FIG. 2, the fuel cell system according to Embodiment 2 of the present invention is basically the same as the fuel cell system according to Embodiment 1, but the second condensed water path is formed at the lower end of the merge path 70. 92 is connected, and the downstream end of the second condensed water path 92 is provided with a second water recovery unit 91. The second water recovery unit 91 has a second drainage path 93 connected to the outside of the fuel cell system 100, and excess water in the second water recovery unit 91 is discharged from the second drainage path 93 to the fuel cell system. Drained out of 100. In addition, although the 1st water collection | recovery part 85 and the 2nd water collection | recovery part 91 are set as the respectively independent structure, when the water surface in the 1st water collection | recovery part 85 rises more than predetermined | prescribed height, it is predetermined | prescribed height. A drainage path that connects the first water recovery unit 85 and the second water recovery unit 91 may be provided so that the above excess water is drained to the second water recovery unit 91.

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

  The first water recovery unit 85 is configured to store condensed water generated by condensation of combustion exhaust gas and cathode off gas flowing in the exhaust path 77 and the combustion exhaust gas flow path 80, and the second water recovery unit 91 includes an external pipe 76, Condensed water generated by condensation of combustion exhaust gas and cathode off-gas flowing in the confluence path 70 and rainwater flowing in from the open end of the external pipe 76 are stored, and the water level in the second water recovery unit 91 exceeds a predetermined height. When it rises, excess water of a predetermined height or higher is drained to the outside of the fuel cell system 100 via the second drainage path 93.

  Further, the second water recovery unit 91, the second condensed water path 92, and the second drainage path 93 use the water in the second water recovery unit 91 to discharge exhaust gas discharged from the fuel cell system 100, It is configured so as to have a water sealing function that prevents the fuel cell system 100 (housing 12) from flowing into the indoors via the second drainage path 93. Specifically, the second condensed water path 92 is inserted to the lower side in the second water recovery section 91, and the second drainage path 93 of the second water recovery section 91 is connected from the lower end of the second condensed water path 92. The water pressure generated by the difference in height between the water surface in the second condensed water path 92 and the water surface in the second water recovery unit 91 is higher than the back pressure applied to the third connection unit 94. It is configured with consideration given to increasing the size. In the fuel cell system according to the second embodiment, the water recovery unit is used as the water seal configuration. However, the configuration is not limited to this, and a configuration using, for example, a U-shaped tube may be used as long as the water seal function can be realized. .

  In particular, the condensed water generated in the merge path 70 flows down to the third connection portion 94 and is stored in the second water recovery section 91 via the second condensed water path 92. Further, even when rainwater flows into the merge path 70, the rainwater is stored in the second water recovery unit 91. Therefore, since the second water recovery unit 91 is always replenished with water, the water sealing function can always be exhibited at normal times. Further, excess condensed water stored more than necessary is drained out of the housing 12 through the second drainage path 93. As a result, the exhaust gas of the fuel cell system 100 is not discharged outside the casing 12 of the fuel cell system 100 from the second drainage path 93 by the water sealing function of the second water recovery unit 91.

  In the unlikely event that the water in the second water recovery unit 91 is insufficient and the water sealing function cannot be exhibited, the lower end of the merging path 70 has the third connection unit 94 connected to the second water recovery unit 91, A first connection portion 89 connected to the ventilation path 75 is provided on the upstream side of the merging path 70, that is, the lower side surface of the merging path 70 extending in the vertical direction, and the merging path 70 extends downstream in the merging path 70, that is, in the vertical direction. Since the second connection portion 90 connected to the exhaust passage 77 is provided on the upper side surface of the exhaust gas, the combustion exhaust gas from the exhaust passage 77 is discharged to the second condensed water passage 92 as long as the ventilation fan 13 is operating. The second water recovery unit 91 and the second condensed water path 92 are not discharged out of the housing 12. The condensed water generated in the exhaust path 77 is collected by the first water collecting unit 85, and the condensed water in the merging path 70 and the rainwater flowing into the merging path 70 are collected by the second water collecting unit 91. However, a configuration in which part of the condensed water generated in the exhaust path 77 is recovered by the second water recovery unit 91 may be used.

As described above, in the fuel cell system shown in the second embodiment, the condensed water generated by the condensation of the combustion exhaust gas and the cathode off-gas flowing in the confluence path 70 and the rainwater flowing in from the open end of the external pipe 76 are used. 2 Since the condensed water path 92 can be discharged out of the casing 12 of the fuel cell system 100 through the second water recovery section 91 and the second drainage path 93, a large amount of condensed water and rainwater flow into the merge path 70. Even in this case, the water in the merging path 70 does not overflow, and the water does not flow back through the ventilation path 75, so that the backflow prevention device 20 can be prevented from being stuck and the ventilation fan 13 from being deteriorated by rust.
Further, even when the pressure of the merging path 70 rises due to, for example, the external pipe 76 of the fuel cell system 100 being blocked, the second condensate water path 92 where the exhaust gas of the fuel cell system 100 is the drainage path of the merging path 70. Can be prevented from leaking indoors through the second water recovery part 91 and the second drainage path 93.

(Embodiment 3)
FIG. 3 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention.
As shown in FIG. 3, the fuel cell system according to the third embodiment of the present invention is basically the same as the fuel cell system according to the second embodiment, but the ventilation gas containing air is supplied from the backflow prevention device 20. The difference is that a weir 96 that prevents water from entering the backflow prevention device 20 is provided at the upstream end of the exhaust ventilation path 75.

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

  Condensate produced by condensation of combustion exhaust gas and cathode off-gas flowing in the confluence path 70 of the fuel cell system 100 and rainwater flowing in from the open end of the external pipe 76 travel along the wall surface of the confluence path 70 and also flow into the ventilation path 75. Come on. However, since the weir 96 that prevents water from entering the backflow prevention device 20 is provided at the upstream end of the ventilation path 75, the condensed water and rainwater flowing into the ventilation path 75 are blocked by the weir 96. The water does not enter the backflow prevention device 20. Furthermore, since the ventilation path 75 has a downward slope with respect to the horizontal plane from the upstream end to the downstream end (inclined), the condensed water and rainwater flowing into the ventilation path 75 are naturally Then, the air is discharged downstream of the ventilation path 75, that is, from the first connection portion 89, which is a connection portion between the ventilation path 75 and the merge path 70, to the merge path 70. The water discharged to the merge path 70 flows down to the third connection portion 94, is stored in the second water recovery section 91 via the second condensed water path 92, and then passes through the second drain path 93 to the fuel cell system. 100 is discharged out of the housing 12.

With the above configuration, the condensed water or rainwater flowing into the ventilation path 75 is blocked by the weir 96 and is naturally discharged to the merging path 70 by the gradient of the ventilation path 75, so that water flows into the backflow prevention device 20. It is possible to prevent the backflow prevention device 20 from being stuck and the ventilation fan 13 from being deteriorated by rust. In the present embodiment, the pipe is inclined from the upstream end to the downstream end of the ventilation path 75 so as to have a downward slope. Any structure may be used as long as water is naturally discharged. For example, a downward slope may be provided by expanding the pipe from the upstream end to the downstream end of the ventilation path 75.

  In the fuel cell system of the present invention, the ventilation gas is first introduced in the merging path, and the combustion exhaust gas is joined downstream of the ventilation gas, so that the combustion exhaust gas containing moisture contacts the backflow prevention device provided in the ventilation path. The backflow prevention device can be prevented from sticking, and the backflow prevention device makes it difficult for the flue gas containing moisture to come into contact with the ventilation fan, preventing deterioration of the ventilation fan due to rust. It can be applied to various types of fuel cell systems including indoor installation.

DESCRIPTION OF SYMBOLS 11 Fuel cell 11A Fuel gas flow path 11B Oxidant gas flow path 12 Case 13 Ventilation fan 14 Fuel processor 14a Reformer 14b Combustor 14c Combustion fan 15 Oxidant gas supply 16 Hole 20 Backflow prevention device 70 Confluence path 71 Fuel gas supply flow path 72 Oxidant gas supply flow path 73 Off fuel gas flow path 74 Off oxidant gas flow path 75 Ventilation path 76 External piping 77 Exhaust flow path 78 Supply air flow path 79 Combustion air supply flow path 80 Combustion exhaust gas flow path 85 1st water collection part 86 1st condensed water path 87 1st drainage path 89 1st connection part 90 2nd connection part 91 2nd water collection part 92 2nd condensed water path 93 2nd drainage path 94 3rd connection part 95 1st 1 Water recovery unit 96 Weir 97 First drainage path 98 Water purification device 100 Fuel cell system 102 Control device 104 Air supply / exhaust mechanism 200 Building

Claims (3)

A generator that generates power using raw fuel;
A merging path connected to the outside,
A ventilation path, one end of which is connected to the first connection portion of the merging path and exhausts ventilation gas including air;
One end is connected to the second connection part located downstream of the ventilation gas with respect to the first connection part of the merging path, and an exhaust path for exhausting exhaust gas containing water vapor and discharged from the generator;
A backflow prevention device that is provided in the ventilation path and prevents backflow of the ventilation gas;
A ventilation device disposed upstream of the backflow prevention device in the ventilation path;
With
The path between the first connection part and the second connection part in the merging path is a structure that is inclined vertically upward or vertically upward from the upstream side to the downstream side of the ventilation gas. ,
The power generation system, wherein a path downstream of the backflow prevention device in the ventilation path has a specific structure that suppresses the flow of liquid from the downstream side to the upstream side of the ventilation path. One end is connected to the third connection part at the lower part of the merge path, further comprising a drain path for draining the condensed water in the merge path to the outside,
The power generation system according to claim 1, wherein the third connection portion is disposed below the first connection portion in a vertical direction.   The power generation system according to claim 1, wherein the specific structure is a structure in which a path is inclined with respect to a horizontal plane or a structure having a step in the path.

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