JP2014002883A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system capable of preventing combustion exhaust gas from flowing out to the outdoor through a drainage path in a water collection section without discharging quality water used in the fuel cell main unit even when a discharge path for discharging the combustion exhaust gas to the outside is clogged.SOLUTION: The fuel cell system includes: a first water collection section 85 for recovering moisture contained in the exhaust gas flowing in a first exhaust path 77 within a fuel cell system 100 as condensed water; and a second water collection section 91 for collecting rain water flowing in a second exhaust path 70 outside the fuel cell system 100 connected to the first exhaust path. The first water collection section 85 and the second water collection section 91 are connected via a first drainage path 87 so that the second water collection section 91 has a water-sealing function. This prevents exhaust gas from leaking from the fuel cell system into a house through the drainage path as well as the quality condensed water used for power generation by the fuel cell main unit is prevented from being discharged.

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 that sandwich the electrolyte (hereinafter, the one that supplies the hydrogen-rich gas is referred to as the anode side), and supplies an oxidant gas such as oxygen-containing air to the other. (Hereinafter, the direction of supplying the oxidant gas is referred to as the 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 one of the methods for generating hydrogen-rich gas (hereinafter referred to as fuel gas) necessary for power generation of a fuel cell, a fuel cell system uses a hydrocarbon-based raw material gas such as city gas or LPG, or a liquid such as methanol or kerosene. Generally, a hydrogen generator having a reforming section for reforming by introducing a hydrocarbon-based raw material together with steam is generally used. That is, it is indispensable to supply water for generating water vapor during the power generation operation of the fuel cell system.

  Usually, water is suitably used as the water supply means for supplying water to the fuel cell system. However, since the performance of the fuel cell system deteriorates over time due to the accumulation of calcium in tap water or corrosion of piping due to chlorine, these components must be removed. Therefore, the conventional fuel cell system is provided with a water purifier including an ion exchange resin or the like.

  However, according to a water purifier equipped with an ion exchange resin or the like, it is possible to sufficiently remove components such as calcium and chlorine contained in water, but the water purification performance of the ion exchange resin and the like deteriorates depending on the use time. To do. That is, in the configuration using this ion exchange resin or the like, it is necessary to frequently maintain the water purifier. This becomes a factor that deteriorates the running cost of the fuel cell system. Therefore, in a conventional fuel cell system, water containing water generated by power generation in the fuel cell or gas containing moisture discharged from a combustor used for heating the fuel cell or the hydrogen-containing gas supply unit (combustion exhaust gas) In many cases, a self-supporting form of water is used in which condensed water obtained by cooling the water is recovered and used.

  Further, the hydrogen generator is provided with a combustion section that burns combustion gas and heats the reforming section. Here, the combustion gas is a gas that is used for combustion in the combustion section, and is not used for power generation in a raw material gas (vaporized in the case of a liquid hydrocarbon-based raw material) or fuel gas, and further in a fuel cell. It refers to a gas containing hydrogen (hereinafter referred to as off-fuel gas). In addition to the combustion gas path for introducing combustion gas, a combustion air path for introducing combustion air is connected to the combustion section. Depending on the flow rate of the combustion gas by a blower such as a combustion air fan, etc. Air is supplied to the combustion section.

  When generating fuel gas with a hydrogen generator, a reforming reaction, which is an endothermic reaction, is carried out by introducing hydrocarbon-based raw material and water into the reforming section and heating the combustion gas in the combustion section. The reforming reaction proceeds by supplying the necessary heat. Further, the hydrogen generator is provided with a carbon monoxide reduction unit as necessary, and the fuel cell is produced as a fuel gas having a high hydrogen concentration by reducing the carbon monoxide concentration in the fuel gas generated in the reforming unit. To the anode side.

  In the fuel cell system, air is supplied to the cathode side of the fuel cell as an oxidant gas by a blower such as an air blower (hereinafter referred to as “cathode air” as appropriate).

  Also, the air used in the fuel cell system, that is, the air necessary for burning the combustion gas in the combustion section, and the air supplied as the oxidant gas to the cathode side of the fuel cell are supplied from the outside of the fuel cell system. In addition, the combustion exhaust gas generated by burning the combustion gas in the combustion section, and the air consumed oxygen by the partial power generation discharged from the cathode side of the fuel cell (hereinafter referred to as off-oxidant gas as appropriate) Is discharged from the fuel cell system to the outside. Exhaust gas (combustion exhaust gas and off-oxidant gas) discharged from these fuel cell systems contains water vapor generated by combustion and water vapor generated by power generation of the fuel cell.

  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 Document 1). In the fuel cell system disclosed in Patent Document 1, a water tank is provided for storing the condensed water generated while the exhaust gas containing water vapor discharged from the fuel cell system is cooled while flowing through the exhaust path. Yes.

  FIG. 6 is a configuration diagram of the fuel cell system disclosed in Patent Document 1. In FIG.

  As shown in FIG. 6, the intake / exhaust device of the fuel cell system disclosed in Patent Document 1 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 which is a water storage part 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).

  By securing the water level in the water tank 51, the mixed exhaust (that is, the exhaust gas of the fuel cell system) 47 can be prevented from flowing out of the main body 30 by sealing with water.

JP 2006-253020 A

  However, in the configuration such as the fuel cell system disclosed in Patent Document 1, the inner pipe of the double-pipe duct is blocked, so that a pressure higher than expected is applied to the water tank, and the water in the water tank is reduced. Or all the water in the water tank is drained. As a result, the water sealing function cannot be performed, and the exhaust gas of the fuel cell system leaks indoors through the drainage path, and the double pipe duct extends to the outside, so rainwater may flow in. There was a problem that the water quality was not good for use in power generation of the battery body.

  The present invention solves the above-described conventional problems, and condenses with good water quality are collected in the first water recovery unit and rainwater is collected in two in the second water recovery unit, and water is collected in the second water recovery unit. It has a sealed structure. As a result, even when the pressure in the discharge path rises due to the blockage of the discharge path of the fuel cell system, the water of the first water recovery unit with good water quality used for power generation of the fuel cell main body is not discharged. An object of the present invention is to provide a fuel cell system that can prevent exhaust gas from the fuel cell system from leaking indoors through a drainage path.

  In order to solve the above-described conventional problem, the second water recovery unit of the fuel cell system according to the present invention is a water seal that seals water so that the exhaust gas does not flow from the second condensed water path to the second drainage path. It has a structure.

  As a result, even when the pressure in the discharge path rises due to the blockage of the discharge path of the fuel cell system, the fuel cell system does not discharge condensed water with good water quality used for power generation of the fuel cell body. It is possible to prevent the exhaust gas from leaking indoors through the drainage path. Further, by collecting the condensed water with good water quality into the first water recovery unit and the rainwater into the second water recovery unit in two parts, the first water recovery unit with good water quality is used for power generation of the fuel cell body. Only water can be used.

  According to the fuel cell system of the present invention, even when the pressure in the discharge path rises due to the blockage of the discharge path of the fuel cell system, the condensed water with good water quality used for power generation of the fuel cell body is discharged. In addition, the exhaust gas of the fuel cell system can be prevented from leaking indoors through the drainage path.

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 fuel cell system according to Embodiment 4 of the present invention. Schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention. Schematic diagram showing the schematic configuration of a conventional fuel cell system

A first invention includes a fuel cell having an anode and a cathode and generating power using a hydrogen-containing gas and an oxidant gas, an anode exhaust gas discharged from the anode side of the fuel cell, and an exhaust gas discharged from the cathode side of the fuel cell Connected to a first exhaust path for exhausting at least one exhaust gas of the cathode exhaust gas, a housing for housing the fuel cell and the first exhaust path, and a downstream end of the first exhaust path, A second exhaust path that exhausts the exhaust gas discharged from the exhaust path to the outside of the housing, and moisture that is connected to the first exhaust path and that flows through the first path is condensed and generated. A first condensed water path for discharging condensed water and a path downstream of the first condensed water path of the first exhaust path or the second exhaust path, and water in the second exhaust path A second condensed water path for discharging, a first water collecting section connected to the first condensed water path and collecting water, and a second water collecting section connected to the second condensed water path and collecting water. And a second drainage path for discharging water from the second water recovery section and to the outside of the housing. And the said 2nd water collection | recovery part has a water seal structure sealed with water so that the said waste gas may not flow from the said 2nd condensed water path | route to the said 2nd drainage path.

  As a result, the condensed water with good water quality is collected in the first water collecting part and the rainwater is collected in two parts in the second water collecting part. Only water can be used, and even when the pressure in the discharge path rises due to the blockage of the discharge path of the fuel cell system, etc., the condensed water of good quality used for power generation of the fuel cell body is not discharged. In addition, the exhaust gas of the fuel cell system can be prevented from leaking indoors through the drainage path.

  In a second aspect of the invention, in particular, in the fuel cell system of the first aspect of the invention, the first water recovery section includes a first drainage path for discharging water from the first water recovery section to the second condensed water path. As a result, excess water from the first water recovery unit can be drained to the second water recovery unit, and condensed water with good water quality is supplied to the first water recovery unit, and rainwater is supplied to the second water recovery unit. Collect separately. As a result, only the water of the first water recovery section with good water quality can be used for power generation of the fuel cell main body, and when the pressure in the discharge path rises due to the discharge path of the fuel cell system being blocked, etc. However, it is possible to prevent the exhaust gas of the fuel cell system from leaking indoors through the drainage channel without discharging the condensed water having good water quality used for power generation of the fuel cell main body.

  According to a third aspect of the present invention, in the fuel cell system according to any one of the first and second aspects, the first water recovery unit is configured to prevent the exhaust gas from flowing from the first condensed water path to the first drainage path. By having the water-sealing structure to be sealed, the pressure acting on the two water surfaces separating the water-sealing structure of the first water recovery unit becomes equal, so the water level of the first water recovery unit does not fluctuate due to the influence of the pressure . That is, even when the pressure in the discharge path rises due to the blockage of the discharge path of the fuel cell system, the fuel cell system discharges without discharging the high-quality condensed water used for power generation of the fuel cell body. Gas can be prevented from leaking indoors through the drainage path.

  A fourth invention is the fuel cell system according to any one of the first to third inventions, comprising a combustor that burns combustible gas and combustion air and discharges combustion exhaust gas. The first exhaust path exhausts at least one of the anode exhaust gas discharged from the anode side of the fuel cell, the cathode exhaust gas discharged from the cathode side of the fuel cell, and the combustion exhaust gas. Thus, the exhaust gas of the fuel cell system including the combustion exhaust gas can be prevented from leaking indoors through the drainage path.

  According to a fifth invention, in the fuel cell system according to any one of the first to fourth inventions, the water in the first water recovery unit is purified by including a water purification device that purifies the water in the first water recovery unit. By doing so, the quality of the water used for the power generation of the fuel cell body can be improved.

  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 is connected to a supply / exhaust mechanism 104 having a second exhaust path 70 and an air supply passage 78.

  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 or the like 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. Further, the control device 102 may be configured by a microcomputer, and may be configured by an MPU, a PLC (programmable logic controller), a logic circuit, or the like.

  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 first exhaust path 77 inside the fuel cell system 100 and the fuel cell system 100 are bordered by the hole 16. A pipe constituting the external second exhaust path 70 is connected. In the present embodiment, the pipe constituting the second exhaust path 70 is configured as a double pipe disposed inside the pipe constituting the air supply flow path 78. Any structure may be used as long as the first exhaust path 77 and the second exhaust path 70 outside the fuel cell system 100 are connected to each other.

  The second exhaust path 70 is formed so as to extend to the outside of the building 200, and its downstream end (opening) is open to the atmosphere. The air supply channel 78 has a downstream end connected to the housing 12 and an upstream end (opening) opened to the atmosphere. 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 mixing unit 90 described later. Oxidant gas that has not been used in the fuel cell 11 (hereinafter referred to as off-oxidant gas) is supplied from the outlet of the oxidant gas flow path 11B to the off-oxidant gas flow path 74, the mixing unit 90, and the first exhaust path 77 through the second. It is discharged out of the building 200 through the exhaust path 70.

  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 from the mixing unit 90 to the second exhaust path 70 via the first exhaust path 77. The combustion exhaust gas discharged to the second exhaust path 70 flows through the second exhaust path 70 and is discharged outside the fuel cell system 100 (building 200).

  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 mixing unit 90 via the ventilation channel 75, and is connected to the first exhaust path 77 on the downstream side of the mixing unit 90. 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 passage 75. Then, the air is exhausted outside the building 200 through the mixing unit 90, the first exhaust path 77, and the second exhaust path 70, 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.

  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 by the mixing unit 90 in the housing 12, then discharged to the first exhaust path 77, and discharged to the outside via the second exhaust path 70 outside the fuel cell system 100. That is, a combustion exhaust gas flow path 80, an off-oxidant gas flow path 74, and a ventilation flow path 75 are connected to the mixing unit 90, and a first exhaust path 77 through which combustion exhaust gas, off-oxidant gas, and air from a ventilation fan merge. Part of

  Further, a first water recovery unit 85 is provided below the mixing unit 90, and the mixing unit 90 and the first water recovery unit 85 are connected by a first condensed water path 86.

The mixing unit 90 has a shape such as an inclination so that the condensed water generated when the temperature of the exhaust gas decreases in the mixing unit 90 flows into the first water recovery unit 85 via the first condensed water path 86. The connection positions of the off-oxidant gas channel 74, the combustion exhaust gas channel 80, the ventilation channel 75, the mixing unit 90, the first exhaust channel 77, and the first condensed water channel 86 are configured in consideration. The first exhaust path 77
Is installed so as to have an upward slope toward the outdoors.

  A second water recovery unit 91 is provided below the connection part 89 between the first exhaust path 77 and the second exhaust path 70, and is connected by a second condensed water path 92. Further, a second drainage passage 93 having one end communicating with the outside of the housing 12 is connected to the upper part of the second water recovery unit 91.

  The first water recovery section 85 is configured to store the condensed water in the first exhaust path 77 that has flowed in via the first condensed water path 86, and the second water recovery section 91 includes the second condensed water path 92. When the water level in the second water recovery unit 91 rises to a predetermined height or more with the configuration in which rainwater that flows in through the water is stored, excess water of a predetermined height or more passes through the second drainage path 93. The fuel cell system 100 is configured to be drained to the outside.

  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 height difference between the water level in the second condensed water path 92 and the water level in the second water recovery unit 91 is greater than the back pressure applied to the connection part 89. It is configured with consideration. In the fuel cell system according to the first 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. .

  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 channel 75.

  Therefore, 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 mixing unit 90 as exhaust gas. The first exhaust path 77, the connecting portion 89, and the second exhaust path 70 are discharged to the outside.

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 mixing unit 90. 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.

  Also 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) are mixed by the mixing unit 90, the first exhaust path 77, the connection unit 89, and the second. It is cooled until it is discharged to the outside of the building 200 through the exhaust path 70, and condensed water is generated. In particular, the condensed water generated in the second exhaust path 70 flows down to the connection part 89 and is stored in the second water recovery part 91 via the second condensed water path 92. Further, even when rainwater flows into the second exhaust 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.

  As described above, the condensed water generated in the mixing section 90 and the first exhaust path 77 is recovered by the first water recovery section 85 and flows into the condensed water generated in the second exhaust path 70 and the second exhaust path 70. The rainwater thus collected is stored in the second water recovery unit 91. In general, since the second exhaust path 70 is often an existing facility in a building, the condensed water in the second exhaust path 70 is contaminated. That is, since condensed water with good water quality used for power generation of the fuel cell main body can be secured in the first water recovery unit 85, fuel gas is generated from the raw material by the reformer 14a of the fuel processor 14 By utilizing this for the reforming reaction to be performed, the water self-sustained operation of the fuel cell system 100 becomes possible, and the operation can be continued.

  Further, even when the pressure in the first exhaust path 77 rises due to blockage in the second exhaust path 70 or the like, the second drainage path 93 of the second water recovery unit 91 starts from the lower end of the second condensed water path 92. The water pressure generated by the difference in height between the water level in the second condensed water path 92 and the water level in the second water recovery unit 91 is greater than the back pressure applied to the connection unit 89. By taking this into consideration, the exhaust gas is prevented from flowing out of the fuel cell system 100. Furthermore, even when the pressure in the first exhaust path 77 rises, the water level does not fluctuate due to the pressure of the first water recovery unit 85, so the water used in the fuel cell system 100 is not affected by the pressure. Never lose.

  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 condensed water of the first water recovery unit 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.

Further, the condensed water generated in the first exhaust path 77 is recovered by the first water recovery unit 85, and the condensed water in the second exhaust path 70 and the rainwater flowing into the second exhaust path 70 are recovered by the second water recovery unit 91. However, a configuration in which a part of the condensed water generated in the first exhaust path 77 is recovered by the second water recovery unit 91 may be used.

  As described above, the fuel cell system shown in the first embodiment is used for power generation of the fuel cell main body even when the pressure in the discharge path rises due to the discharge path of the fuel cell system being blocked. It is possible to prevent the exhaust gas of the fuel cell system from leaking indoors through the drainage channel without discharging condensed water with good water quality. In addition, the condensed water with good water quality is collected in the first water recovery unit, and the condensed water and rainwater mixed with dirt in the pipeline are collected in two in the second water recovery unit. Only the water of the first water recovery unit with good water quality can be used.

(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 the second embodiment of the present invention is basically the same as the fuel cell system according to the first embodiment. 2 The point from which the 1st drainage path 87 connected with the 2 condensed water path | route 92 is provided differs.

  A second water recovery unit 91 is provided below the connection part 89 between the first exhaust path 77 and the second exhaust path 70, and is connected by a second condensed water path 92. The second condensed water path 92 is also connected to the first drainage path 87. Further, a second drainage passage 93 having one end communicating with the outside of the housing 12 is connected to the upper part of the second water recovery unit 91.

  The 1st water collection part 85 is the composition which stores the condensed water in the 1st exhaust passage 77 which flowed in via the 1st condensation water path 86, and the water level in the 1st water collection part 85 is more than predetermined height. When it rises, excess water of a predetermined height or higher is drained to the second condensed water path 92 via the first drainage path 87 and stored in the second water recovery unit 91.

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

  A first water recovery unit 85 and a second water recovery unit 91 are provided, and excess water in the first water recovery unit 85 is drained to the second water recovery unit 91 via the first drainage path 87, so that the second It is possible to prevent water in the water recovery unit 91 from flowing into the first water recovery unit 85.

  Further, even when the pressure in the first exhaust path 77 rises, the pressure in the first water recovery section 85 is configured to escape to the second condensed water path 92 through the first drainage path 87, and the influence of the pressure Accordingly, the water level does not fluctuate, so that the water used in the fuel cell system 100 is not lost due to the influence of pressure.

(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 Embodiment 3 of the present invention is basically the same as the fuel cell system according to Embodiment 1, except that the exhaust gas discharged from the fuel cell system 100 is In order to prevent the first water collecting path 95 from flowing out from the first condensed water path 86 to the first drainage path 87, a water sealing function is provided.

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

  Combustion exhaust gas discharged from the fuel cell system 100, off-oxidant gas, and moisture in the gas in the case 12 due to the operation of the ventilation fan 13 are provided below the mixing unit 90 in the case 12. 1 Condensed water is recovered in the water recovery unit 95. Even when the pressure in the first exhaust path 77 rises due to the blockage in the second exhaust path 70 or the like, the first water recovery section 95 is separated through the first drainage path 87 across the water seal configuration. Since the pressure acting on the water surface in the first water recovery unit 95 is equal to the pressure acting on the water surface of the first water recovery unit 95 via the first condensed water path 86, the first water recovery unit is affected by the pressure. The water level in 95 does not fluctuate. That is, water used in the fuel cell system 100 is not lost due to the influence of pressure.

  In the fuel cell system of the second embodiment, the first water recovery unit and the second recovery unit have a water sealing function. However, the configuration is not limited to this configuration, and the water sealing function is provided. If so, either one or both may have a U-shaped tube configuration.

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

  As shown in FIG. 4, the fuel cell system 100 according to Embodiment 4 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 3, but rainwater in the second exhaust path 70. The second water recovery part 91 and the second condensed water path 92 for recovering the condensed water are configured outside the fuel cell system 100, and one end of the first drainage path 97 communicates with the outside of the housing 12. Is different.

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

  Combustion exhaust gas discharged from the fuel cell system 100, off-oxidant gas, and moisture in the gas in the case 12 due to the operation of the ventilation fan 13 are provided below the mixing unit 90 in the case 12. 1 Collected as condensed water in the water recovery unit 95. On the other hand, the condensed water and rainwater in the exhaust gas flowing through the second exhaust path 70 are recovered in the second water recovery part 91 outside the fuel cell system 100 provided below the connection part 89. Excess water in the first water recovery unit 95 is drained to the outdoors via the first drainage path 97, and surplus water in the second water recovery unit 91 is drained to the outdoors via the second drainage path 93. Due to the water sealing function in the second water recovery unit 91, the exhaust gas of the fuel cell system 100 is not discharged outdoors. Moreover, the fuel cell system 100 can be designed compactly by configuring the second water recovery unit 91 outside the fuel cell system 100.

  In the present embodiment, the first drainage path 97 is drained outdoors, but the first drainage path 97 may be connected to the second condensed water path 92 or the second drainage path 93. .

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

  As shown in FIG. 5, the fuel cell system 100 according to Embodiment 5 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 3, but the first water recovery unit 95 has purified water. The difference is that the device 98 is connected.

Combustion exhaust gas discharged from the fuel cell system 100, off-oxidant gas, and moisture in the gas in the case 12 due to the operation of the ventilation fan 13 are provided below the mixing unit 90 in the case 12. It collect | recovers as condensed water in 1 water collection | recovery part 95, and purifies by passing the water in the 1st water collection | recovery part 95 through the water purifier 98. The purified water is used for the reforming reaction in the reformer 14a. Compared with the case where tap water is used, it is possible to prevent the performance of the fuel cell system from deteriorating over time due to calcium accumulation or corrosion of piping due to chlorine.

  In the fuel cell system of the present invention, even when the pressure in the discharge path rises due to the discharge path of the fuel cell system being blocked, etc., the condensed water with good water quality used for power generation of the fuel cell body is not discharged. Since the exhaust gas of the fuel cell system can be prevented from leaking indoors through the drainage path, it can be applied to various forms 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 70 Second exhaust path 71 Fuel gas Supply channel 72 Oxidant gas supply channel 73 Off-fuel gas channel 74 Off-oxidant gas channel 75 Ventilation channel 77 First exhaust channel 78 Air supply channel 79 Combustion air supply channel 80 Combustion exhaust gas channel 85 First Water recovery part 86 First condensate path 87 First drainage path 89 Connection part 90 Mixing part 91 Second water recovery part 92 Second condensate path 93 Second drainage path 95 First water recovery part 97 First drainage path 98 Clean water Device 100 Fuel cell system 102 Control device 104 Air supply / exhaust mechanism 200 Building

Claims (5)

A fuel cell having an anode and a cathode and generating electricity using a hydrogen-containing gas and an oxidant gas;
A first exhaust path for exhausting at least one of the anode exhaust gas discharged from the anode side of the fuel cell and the cathode exhaust gas discharged from the cathode side of the fuel cell;
A housing for housing the fuel cell and the first exhaust path;
A second exhaust path connected to a downstream end of the first exhaust path and exhausting the exhaust gas discharged from the first exhaust path to the outside of the housing;
A first condensed water path connected to the first exhaust path and discharging condensed water generated by condensation of moisture contained in the exhaust gas flowing through the first path;
A second condensed water path that is connected to a path downstream of the first condensed water path in the first exhaust path or the second exhaust path and discharges water in the second exhaust path;
A first water recovery unit connected to the first condensed water path and recovering water;
A second water recovery unit connected to the second condensed water path and recovering water;
A second drainage path for discharging water from the second water recovery section to the outside of the housing;
With
The second water recovery unit has a water seal structure that seals water so that the exhaust gas does not flow from the second condensed water path to the second drainage path.
Fuel cell system.   2. The fuel cell system according to claim 1, wherein the first water recovery unit includes a first drainage path that discharges water from the first water recovery part to the second condensed water path.   3. The fuel cell system according to claim 1, wherein the first water recovery unit has a water seal structure that seals water so that the exhaust gas does not flow from the first condensed water path to the first drainage path. A combustor that combusts combustible gas and combustion air to discharge combustion exhaust gas,
The first exhaust path exhausts at least one of exhaust gas discharged from the anode side of the fuel cell, cathode exhaust gas discharged from the cathode side of the fuel cell, and combustion exhaust gas,
The fuel cell system according to any one of claims 1 to 3.   The fuel cell system of any one of Claims 1-4 provided with the water purifier which purifies the water in a said 1st water collection | recovery part.