JP2008251216A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system; increasing amount of moisture recovered from air ejected from an air path, purifying water by diluting the water inside a water container by making excessive water discardable, obtaining sufficient heat for heating even in low temperature making an exclusive heating system unnecessary, and with configuration for an apparatus which is simple as well as providing high space efficiency. <P>SOLUTION: The fuel cell system includes: a fuel cell stack in which fuel cells holding electrolyte layers with fuel electrodes and oxygen electrodes are laminated with a separator for which the air path is formed along the oxygen electrodes, a water supplying nozzle supplying the water into the air supplied in the air path, a condenser condensing and removing the moisture in the ejected air from the air path, a water circulation system recovering the water removed by the condenser and supplying it to the water supplying nozzle, a cooling medium supplying system supplying cooling medium to the condenser, and a heating system heating the interior of a vehicle by recovering discarded heat from the cooling medium supplying system. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system.

  Conventionally, since fuel cells have high power generation efficiency and do not emit harmful substances, they have been put into practical use as power generators for industrial and household use, or as power sources for artificial satellites and spacecrafts. Development is progressing as a power source for vehicles such as buses, trucks, passenger carts, and luggage carts. The fuel cell may be an alkaline aqueous solution (AFC), phosphoric acid (PAFC), molten carbonate (MCFC), solid oxide (SOFC), direct methanol (DMFC), etc. Although good, a polymer electrolyte fuel cell (PEMFC) is common.

  In this case, the solid polymer electrolyte membrane is sandwiched between two gas diffusion electrodes and integrated to join. When one of the gas diffusion electrodes is used as a fuel electrode (anode electrode) and hydrogen gas as fuel is supplied to the surface, hydrogen is dissociated into hydrogen ions (protons) and electrons, and the hydrogen ions are converted into a solid polymer electrolyte. Move the membrane. Further, when the other of the gas diffusion electrodes is an oxygen electrode (cathode electrode) and air as an oxidant is supplied to the surface, oxygen in the air is combined with the hydrogen ions and electrons to generate water. The An electromotive force is generated by such an electrochemical reaction.

And in the fuel cell system for vehicles, the system using the waste heat which the cooling system for cooling a solid polymer electrolyte membrane generate | occur | produces in order to heat a vehicle interior is proposed (for example, patent document 1). reference.).
JP 2004-146144 A

  However, in the conventional fuel cell system, the interior of the vehicle is heated by the waste heat that has cooled the solid polymer electrolyte membrane. Therefore, when the temperature is low, such as in winter, the temperature of the solid polymer electrolyte membrane increases so much. In addition, since it is not necessary to operate the cooling system so much, it becomes difficult to obtain sufficient heat necessary for heating the vehicle interior.

  The present invention solves the problems of the conventional fuel cell system and condenses moisture in the air discharged from the air flow path in the fuel cell system for supplying water to the air supplied to the air flow path. By using the waste heat of the refrigerant supply system that cools the condenser to be removed for heating the interior of the vehicle, the amount of water recovered from the air exhausted from the air flow path is increased, and excess water is removed. By disposing it, the water in the water storage section can be diluted to purify the water, and sufficient heat for heating can be obtained even at low temperatures, eliminating the need for a dedicated heating system. An object of the present invention is to provide a fuel cell system with a simple device configuration and high space efficiency.

  Therefore, in the fuel cell system of the present invention, a fuel cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxygen electrode is stacked with a separator in which an air flow path is formed along the oxygen electrode. A battery stack, a water supply nozzle for supplying water to the air supplied to the air flow path, a condenser for condensing and removing moisture in the air discharged from the air flow path, and the condenser A water circulation system that collects the removed water and supplies it to the water supply nozzle, a refrigerant supply system that supplies refrigerant to the condenser, and heating that recovers waste heat of the refrigerant supply system and heats the interior of the vehicle System.

  In another fuel cell system of the present invention, the refrigerant supply system further includes a compressor that compresses the gas-phase refrigerant, a capacitor that liquefies the refrigerant compressed by the compressor, and vaporizes the liquefied refrigerant. And the evaporator is disposed in the condenser, and the heating system uses heat of the condenser.

  In still another fuel cell system of the present invention, the heating system further includes a heating air duct that introduces air that has passed through the condenser into a vehicle interior, and cool air is supplied to the heating air duct. A cool air introduction conduit for selectively introducing and a warm air exhaust conduit for selectively discharging warm air are connected, and a warm air cooling conduit for selectively allowing the gas-phase refrigerant discharged from the evaporator to pass therethrough is disposed. Has been.

  In still another fuel cell system of the present invention, the water circulation system further includes drainage means, and the circulating water replaced by the water removed and recovered by the condenser is discharged from the drainage means. .

  In still another fuel cell system of the present invention, the water circulation system further includes a water storage container for storing the circulating water, and when the circulating water in the water storage container reaches a predetermined amount or more, the excess circulating water is provided. Is discharged from the drainage means.

  According to the configuration of claim 1, the amount of moisture recovered from the air discharged from the air flow path can be increased, sufficient heating heat can be obtained, and a dedicated heating system is unnecessary, and the device The configuration can be simplified, and a fuel cell system with high energy efficiency and space efficiency can be obtained.

  According to the configuration of the second aspect, the evaporator can effectively cool the air passing through the condenser, and the moisture in the air can be efficiently condensed and recovered.

  According to the configuration of the third aspect, the air that has passed through the condenser can efficiently heat the interior of the vehicle using waste heat and appropriately control the temperature of the air introduced into the interior of the vehicle. can do.

  According to the configuration of claim 4, by replacing the circulating water with the recovered water, the impurity concentration of the circulated water can be reduced, and water with a low impurity concentration can be supplied to the fuel cell stack. And the performance degradation of the fuel cell stack can be suppressed.

  According to the structure of Claim 5, the quantity of circulating water can be hold | maintained appropriately and the quantity of water required for a fuel cell can be supplied reliably.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a fuel cell system according to an embodiment of the present invention. FIG. 2 is a diagram showing a configuration of a main part of the fuel cell system according to the embodiment of the present invention. is there.

  In the figure, reference numeral 11 denotes a fuel cell stack as a fuel cell device, which is used as a power source for vehicles such as passenger cars, buses, trucks, passenger carts and luggage carts. Here, the vehicle is equipped with a large number of auxiliary devices that consume electricity, such as lighting devices, radios, and power windows, which are used even when the vehicle is stopped. Since the output range is extremely wide, it is desirable to use the fuel cell stack 11 as the power source and the capacitor unit 63 as the power storage means in combination.

  The fuel cell stack 11 may be an alkaline aqueous solution type, phosphoric acid type, molten carbonate type, solid oxide type, direct type methanol, or the like, but is preferably a solid polymer type fuel cell. .

  More preferably, PEMFC (Proton Exchange Membrane Fuel Cell) type fuel cell or PEM (Proton Exchange Membrane) using hydrogen gas as fuel gas, that is, anode gas, and oxygen or air as oxidant, that is, cathode gas. ) Type fuel cell. Here, the PEM type fuel cell is generally a fuel cell in which a catalyst, an electrode, and a separator are combined on both sides of a solid polymer electrolyte membrane as an electrolyte layer that moves ions such as protons. Are composed of a plurality of stacks connected in series.

  In the present embodiment, the fuel cell stack 11 has a plurality of cell modules (not shown). The cell module includes a unit cell (MEA) as a fuel cell, and electrically connects the unit cells to each other, and introduces a hydrogen gas channel and an anode gas introduced into the unit cell. The separator that separates the flow path of air as gas is a set, and a plurality of sets are stacked in the thickness direction. In the cell module, unit cells and separators are stacked in multiple stages so that the unit cells are arranged with a predetermined gap (gap) therebetween.

  In this case, the cell modules are connected to each other so that they can conduct electricity and the fuel flow path, that is, the hydrogen gas flow path is continuous.

  The unit cell is composed of an air electrode as an oxygen electrode provided on the side of the solid polymer electrolyte membrane as the electrolyte layer and a fuel electrode provided on the other side. The air electrode includes an electrode diffusion layer made of a conductive material that permeates while diffusing the reaction gas, and a catalyst layer that is formed on the electrode diffusion layer and is supported in contact with the solid polymer electrolyte membrane. In addition, the current collector in contact with the electrode diffusion layer on the air electrode side of the unit cell, and the air electrode side collector as a net-like current collector formed with a large number of openings through which a mixed flow of air and water is transmitted; And a fuel electrode side collector as a net-like current collector for contacting the electrode diffusion layer on the fuel electrode side of the unit cell and leading out current to the outside.

  In the unit cell, water moves. In this case, when a fuel gas, that is, hydrogen gas as an anode gas is supplied into the fuel chamber of the fuel electrode side collector, hydrogen is decomposed into hydrogen ions and electrons, and the hydrogen ions are accompanied by proton-entrained water. Permeates the electrolyte membrane. Further, when the air electrode is a cathode electrode and an oxidant, that is, air as a cathode gas is supplied into an oxygen chamber as an oxidant flow path, oxygen in the air is combined with the hydrogen ions and electrons, Water is produced. Moisture permeates through the solid polymer electrolyte membrane as reverse diffusion water and moves into the fuel chamber of the fuel electrode side collector. Here, the reverse diffusion water means that water generated in an oxygen chamber as an air channel diffuses into the solid polymer electrolyte membrane and permeates through the solid polymer electrolyte membrane in the direction opposite to the hydrogen ions. It has penetrated into the fuel chamber.

  In the figure, an apparatus for supplying hydrogen gas as a fuel gas to the fuel cell stack 11 and an apparatus for supplying air as an oxidant are shown. Although hydrogen gas, which is fuel taken out by reforming methanol, gasoline, or the like by a reformer (not shown), can be directly supplied to the fuel cell stack 11, it is stable and sufficient even during high-load operation of the vehicle. In order to be able to supply an amount of hydrogen gas, it is desirable to supply the hydrogen gas stored in the fuel storage means 21. Thereby, the hydrogen gas is always sufficiently supplied at a substantially constant pressure, so that the fuel cell stack 11 can follow the fluctuation of the load of the vehicle and supply a necessary current. .

  Hydrogen gas is stored in a container containing a hydrogen storage alloy, a container containing a hydrogen storage liquid such as decalin, a fuel storage means 21 such as a hydrogen gas cylinder, a first fuel supply line 22 as a fuel supply line, and The fuel is supplied to an inlet of a fuel gas flow path of the fuel cell stack 11 through a second fuel supply pipe 33 as a fuel supply pipe connected to the first fuel supply pipe 22. The first fuel supply line 22 includes a fuel storage means on-off valve 23, a first pressure sensor 27a, a first fuel pressure adjustment valve 25a, a second fuel pressure adjustment valve 25b, a fuel supply electromagnetic valve 26, and a first A three pressure sensor 27c is provided. The first fuel supply line 22 is connected to a bypass line 22a that bypasses the second fuel pressure regulating valve 25b, and a second pressure sensor 27b and an activation solenoid valve 26a are connected to the bypass line 22a. Arranged.

  In this case, the fuel storage means 21 has a sufficiently large capacity and is capable of always supplying sufficiently high pressure hydrogen gas. In the example shown in the figure, a plurality of, for example, three fuel storage means 21 are provided, and the first fuel supply conduit 22 is divided into a plurality at the portion connected to each fuel storage means 21. It is divided and merges on the way to become one. The fuel storage means 21 may be singular or plural, and may be any number when plural.

  Then, hydrogen gas discharged as an unreacted component from the outlet of the hydrogen gas flow path of the fuel cell stack 11 is discharged out of the fuel cell stack 11 through the first fuel discharge pipe 30. A suction circulation pump 36 as a pump is disposed in the first fuel discharge pipe 30. A hydrogen circulation electromagnetic valve 34 is disposed in the first fuel discharge pipe 30. Further, the end of the first fuel discharge line 30 opposite to the fuel cell stack 11 is connected to the second fuel supply line 33. Thereby, the hydrogen gas discharged out of the fuel cell stack 11 can be recovered, supplied to the hydrogen gas flow path of the fuel cell stack 11 and reused.

  Further, a second fuel discharge line 38 is connected between the fuel cell stack 11 and the suction circulation pump 36 in the first fuel discharge line 30, and the second fuel discharge line 38 has a hydrogen start exhaust gas. An electromagnetic valve 37 is provided so that hydrogen gas discharged from the fuel gas flow path when the fuel cell stack 11 is started can be discharged into the atmosphere. The outlet end of the second fuel discharge pipe 38 is connected to the exhaust manifold 13.

  Further, a third fuel discharge line 38 a having the other end connected to the second fuel discharge line 38 is provided between the suction circulation pump 36 and the hydrogen circulation electromagnetic valve 34 in the first fuel discharge line 30. It is connected. The third fuel discharge line 38a is provided with a reduced-pressure hydrogen discharge valve 37a that is opened when the inside of the fuel cell stack 11 is depressurized. The first fuel discharge pipe 30 is connected to an outside air introduction electromagnetic valve 35 and an air filter 35a so that outside air can be introduced when the fuel cell stack 11 is stopped.

  Here, the first fuel pressure regulating valve 25a and the second fuel pressure regulating valve 25b are those of a butterfly valve, a regulator valve, a diaphragm type valve, a mass flow controller, a sequence valve, etc., but the first fuel pressure regulating valve Any type of hydrogen gas may be used as long as the pressure of the hydrogen gas flowing out from the outlets of 25a and the second fuel pressure regulating valve 25b can be adjusted to a preset pressure. The pressure adjustment may be performed manually, but is preferably performed by an actuator including an electric motor, a pulse motor, an electromagnet, or the like.

  The fuel supply solenoid valve 26, the start-up solenoid valve 26a, the hydrogen circulation solenoid valve 34, and the hydrogen start-up exhaust solenoid valve 37 are so-called on-off types, and are composed of an electric motor, a pulse motor, an electromagnet, and the like. Actuated by an actuator. The fuel storage means original opening / closing valve 23 is operated manually or automatically using an electromagnetic valve. Further, the suction circulation pump 36 may be of any type as long as it can forcibly discharge the reverse diffusion water together with the hydrogen gas and can bring the inside of the fuel gas passage into a negative pressure state. Good.

  On the other hand, the air as the oxidant passes through the air filter 53 and is sucked into the air supply fan 51 as the oxidant supply source, and from the air supply fan 51 through the air supply line 52 and the intake manifold 12. The fuel cell stack 11 is supplied to an oxygen chamber as an oxidant flow path, that is, an air flow path.

  The fuel cell system in the present embodiment is a direct injection type atmospheric pressure fuel cell system, that is, a DWI-FC (Direct Water Injection Fuel Cell) system, which supplies an anode gas under normal pressure and directly supplies water to the fuel cell. It is a polymer electrolyte fuel cell system which cools by spraying. In this case, the pressure of the supplied air is a normal pressure of about atmospheric pressure. The air supply fan 51 may be of any type as long as it can suck and discharge air. The air filter 53 may be of any type as long as it can remove dust, impurities, etc. contained in the air. Note that oxygen can be used as the oxidizing agent instead of air. And the air discharged | emitted from an air flow path is discharged | emitted in air | atmosphere through the exhaust manifold 13 and the condenser 14 as a manifold.

  The air supply pipe 52 is supplied with water sprayed into the air supplied to the air flow path, and water for maintaining the air electrode as the oxygen electrode of the fuel cell stack 11 in a wet state. A supply nozzle 47 is provided. The air electrode and the fuel electrode can be cooled by the sprayed water. Further, the condenser 14 disposed at the end of the exhaust manifold 13 is for condensing and removing moisture in the air discharged from the fuel cell stack 11, and is condensed by the condenser 14. The water thus collected is collected in a water tank 43 as a water storage container through a condensed water discharge pipe 41. The condensed water discharge pipe 41 is provided with a drain pump 42, and the water tank 43 is provided with a level gauge.

  The water in the water tank 43 is supplied to the water supply nozzle 47 through the water supply pipe 46. A water supply pump 44 and a water filter 45 are disposed in the water supply pipe 46. Here, the drainage pump 42 and the water supply pump 44 may be of any type as long as they can suck and discharge water. The condensed water discharge pipe 41, the drainage pump 42, the water tank 43, the water supply pump 44, the water filter 45, and the water supply pipe 46 function as a water circulation system.

  Furthermore, an inverter device 61 as a drive control device as a load and a capacitor unit 63 as a power storage unit are connected in parallel to an electric terminal (not shown) of the fuel cell stack 11. The capacitor unit 63 includes a capacitor (capacitor) such as an electric double layer capacitor. In addition, the said electrical storage means does not necessarily need to be a capacitor, and secondary batteries, such as a lead storage battery, a nickel cadmium battery, a nickel hydride battery, a lithium ion battery, and a sodium sulfur battery, may be what is called a battery (storage battery). Any form may be used as long as it has a function of electrically storing and discharging energy, such as a flywheel, a superconducting coil, and a pressure accumulator. Furthermore, any of these may be used alone, or a plurality of them may be used in combination.

  Further, the inverter device 61 converts a direct current from the fuel cell stack 11 or the capacitor unit 63 into an alternating current and supplies the alternating current to an unillustrated alternating current motor that is a drive source for rotating the wheels of the vehicle. Here, in the fuel cell system, the fuel cell stack 11 or the capacitor unit 63 is connected in parallel to supply current to the inverter device 61. For example, when the vehicle is stopped, the fuel cell stack When the stack 11 is stopped or when the current from the fuel cell stack 11 does not satisfy the required current during high load operation such as on a slope, the current is automatically supplied from the capacitor unit 63 to the inverter device 61. The

  Reference numeral 62 denotes an IGBT unit including an IGBT (insulated gate bipolar transistor) which is a high-speed switching element as a charging switching element, and is a control circuit that controls charging of the capacitor unit 63.

  When the AC motor functions as a power generator during vehicle deceleration operation and generates a so-called regenerative current, the regenerative current is supplied to the capacitor unit 63 during the vehicle deceleration operation, and the capacitor unit 63 Recharged. Further, even when the regenerative current is not supplied, when the capacitor unit 63 is discharged and the terminal voltage decreases, the current generated by the fuel cell stack 11 is automatically supplied to the capacitor unit 63.

  As described above, in the fuel cell system, when the capacitor unit 63 is constantly charged and the current from the fuel cell stack 11 alone does not satisfy the required current, the current is supplied from the capacitor unit 63 to the inverter device 61. Since the vehicle is automatically supplied, the vehicle can travel stably in various travel modes.

  Reference numeral 70 denotes a cooling system as a refrigerant supply system for supplying the refrigerant to the condenser 14, and the same vapor compression as the refrigeration cycle used for refrigerators, freezers, home air conditioners, vehicle air conditioners, and the like. It is a system that uses a refrigeration cycle. Here, 71 is a compressor as a compressor disposed in a refrigerant pipe 72 as a pipe through which the refrigerant flows, and compresses the gas-phase refrigerant. The refrigerant is, for example, a so-called CFC substitute, which is a CFC-like product that has been developed as a substitute for the specific CFCs, but may be any type of refrigerant.

  Further, a condenser 74 as a refrigerant condenser is disposed on the downstream side of the compressor 71 with respect to the refrigerant flow direction in the refrigerant pipe 72. The gas-phase refrigerant compressed to a high-temperature and high-pressure superheated gas state by the compressor 71 is liquefied by being cooled in the condenser 74 to be in a saturated liquid or supercooled liquid state. The compressor 71 is driven by a motor (not shown) that uses a current supplied from the fuel cell stack 11 or the capacitor unit 63.

  An expansion valve 75 is disposed on the downstream side of the compressor 71 with respect to the refrigerant flow direction in the refrigerant pipe 72. Further, the downstream portion of the refrigerant pipe 72 in the refrigerant flow direction is a portion that functions as an evaporator of the refrigeration cycle, and is disposed so as to pass through the inside of the condenser 14. And the refrigerant | coolant which became the state of the saturated liquid or the supercooled liquid is pressure-reduced to the state of a low temperature, low pressure wet steam by passing through the expansion valve 75, and flows into the part which functions as an evaporator. In this portion, the refrigerant absorbs heat from the air passing through the condenser 14 and is sucked into the compressor 71 again.

  On the other hand, the air passing through the condenser 14 is cooled by absorbing heat by the refrigerant. Therefore, the temperature of the air discharged from the fuel cell stack 11 is greatly reduced in the condenser 14 and the saturated water vapor pressure of the air is also greatly reduced. Accordingly, the amount of moisture condensed and recovered from the air Will increase. Thereby, the ability of the condenser 14 to condense the moisture contained in the air is improved, and the recovery efficiency of moisture from the air discharged from the fuel cell stack 11 is improved.

  In addition, the condenser 74 is disposed at or along the air intake of a heating air duct 82 described later, and the refrigerant in the condenser 74 is cooled by the air passing through the heating air duct 82. On the other hand, the air that passes through the heating air duct 82 and is introduced into the vehicle interior is heated by the condenser 74. That is, the interior of the vehicle can be heated by the waste heat of the cooling system 70 that cools the condenser 14.

  In FIG. 2, reference numeral 76 denotes a temperature adjustment pipe. A fluid such as water flows through the inside, and the flow rate of the fluid is adjusted by a flow rate adjustment valve 77 provided in the middle, thereby the condenser 14. The temperature difference between the capacitor 74 and the capacitor 74 can be adjusted as appropriate.

  In the present embodiment, the fuel cell system has an ECU (Electronic Control Unit) 81 described later as a control device. The ECU 81 includes arithmetic means such as a CPU and MPU, storage means such as a magnetic disk and a semiconductor memory, an input / output interface, and the like, and is supplied from various sensors to the fuel gas flow path and the air flow path of the fuel cell stack 11. The air supply fan 51, the first fuel pressure adjustment valve 25a, the second fuel pressure adjustment valve 25b, the fuel supply electromagnetic valve 26, the hydrogen circulation are detected by detecting the flow rate, temperature, output voltage, etc. of hydrogen, oxygen, air, etc. The operations of the solenoid valve 34, the suction circulation pump 36, the drainage pump 42, the water supply pump 44, the compressor 71, and the like are controlled. Further, the ECU 81 supplies fuel and an oxidant to the fuel cell stack 11 in cooperation with other sensors provided in the vehicle and an EV (Electric Vehicle) control ECU (not shown) as a vehicle control means. Centrally control the operation of all devices. The ECU 81 also controls the temperature of air introduced into the vehicle interior in order to heat the vehicle interior.

  Next, a system for controlling the temperature of air introduced into the vehicle interior will be described.

  FIG. 3 is a diagram showing a configuration of a system for controlling the temperature of air introduced into the vehicle interior in the embodiment of the present invention.

  In the example shown in the figure, reference numeral 80 denotes a heating system that heats the interior of the vehicle, and includes a heating air duct 82 that introduces air that has passed through the condenser 74 into the interior of the vehicle. The condenser 74 is disposed at the air inlet of the heating air duct 82 and heats the air introduced into the vehicle interior. A heat insulating wall 91 is disposed between the heating air duct 82 and the outlet of the exhaust manifold 13, and the air cooled by passing through the condenser 14 is cooled. It is desirable to prevent this from happening.

  In the example shown in the figure, the cooling system 70 includes a bypass refrigerant pipe 79 as a warm-air cooling pipe that bypasses a part of the refrigerant pipe 72. The bypass refrigerant pipe 79 bypasses a part of the refrigerant pipe 72 through which the gas-phase refrigerant that passes through the condenser 14 and is sucked into the compressor 71 passes. It is arranged to pass through. Further, since the end of the bypass refrigerant pipe 79 on the refrigerant pipe 72 side is connected to the refrigerant pipe 72 via a three-way valve 78, the opening of the three-way valve 78 can be controlled by bypassing. The flow rate of the refrigerant flowing into the refrigerant pipe 79 can be controlled. By flowing the refrigerant into the bypass refrigerant pipe 79 and controlling the flow rate thereof, the air heated by the condenser 74 can be cooled, and the temperature of the air introduced into the vehicle interior can be adjusted.

  An air filter 83 is preferably provided in the middle of the heating air duct 82 in order to remove dust, impurities and the like contained in the air. The air filter 83 may be of any type as long as dust, impurities, etc. contained in the air can be removed.

  Further, in the middle of the heating air duct 82, it is desirable to connect a cold air introduction conduit 84 and a warm air exhaust conduit 85 in order to adjust the temperature and air volume of the air introduced into the vehicle interior. A cold air introduction amount adjusting valve 84a that adjusts the flow rate of unheated air introduced from the cold air introduction conduit 84 as a temperature control valve at the connection portion of the cold air introduction conduit 84 to the heating air duct 82. Is arranged. By controlling the opening degree of the cold air introduction amount adjusting valve 84a and controlling the flow rate of air introduced from the cold air introduction conduit 84, the temperature and air volume of the air introduced into the vehicle interior can be adjusted. . Note that it is desirable to dispose an air filter 86 similar to the air filter 83 in the cool air introduction conduit 84 in order to remove dust, impurities, and the like contained in the air.

  In addition, a warm air discharge amount adjustment that adjusts the flow rate of air heated by the capacitor 74 discharged from the warm air discharge conduit 85 as a temperature control valve at the connection portion of the warm air discharge conduit 85 to the heating air duct 82. A valve 85a is provided. By controlling the opening degree of the warm air discharge amount adjusting valve 85a to control the flow rate of air discharged from the warm air discharge pipe 85, the temperature and air volume of the air introduced into the vehicle interior can be adjusted. .

  The operations of the three-way valve 78, the cool air introduction amount adjustment valve 84a, and the warm air discharge amount adjustment valve 85a are controlled by the ECU 81. The ECU 81 is introduced into the interior of the vehicle through the heating air duct 82 as indicated by an arrow B in the drawing based on the temperature detected by the temperature sensor 87 disposed in the vicinity of the outlet of the heating air duct 82. The operations of the three-way valve 78, the cold air introduction amount adjustment valve 84a, and the warm air discharge amount adjustment valve 85a are controlled so that the temperature of the air to be set becomes a temperature set by a vehicle occupant or the like.

  Further, in the present embodiment, a water waste pipe 48 as a drain means is connected to the water supply pipe 46, and the circulating water as water circulating through the water circulation system can be discharged and stored in the water tank 43. The extra circulating water that cannot be exhausted is discarded. Thereby, the impurities of the circulating water in the water tank 43 can be diluted to purify the circulating water.

  In the first place, the water recovered from the fuel cell stack 11 inevitably contains impurities. For example, dust, rainwater, aerosol, sea salt, yellow sand, pollen and the like contained in the air supplied to the air flow path are included as impurities. Further, for example, components eluted from various members constituting the fuel cell stack 11 such as pipes, electrode members, gaskets, and adhesives are included as impurities. Therefore, the circulating water circulated by the water circulation system gradually increases the impurity concentration.

  By the way, the amount of water contained in the air discharged from the air flow path is larger than the amount of water supplied by spraying into the air from the water supply nozzle 47. This is because, as described above, in each unit cell, oxygen in the air is combined with hydrogen ions and electrons to generate water, and this generated water is included in the air discharged from the air flow path. . Therefore, the proportion of moisture removed from the air discharged from the fuel cell stack 11 by the condenser 14 increases, and moisture that is discharged from the outlet of the exhaust manifold 13 into the outside air without being condensed by the condenser 14. If the ratio is lower, a larger amount of water than the amount of water supplied from the water supply nozzle 47 can be collected in the water tank 43.

  When the temperature is low as in winter, the temperature of the condenser 14 can be lowered. As a result, the temperature of the air immediately after being discharged from the fuel cell stack 11 and the temperature of the air in the condenser 14 are reduced. The difference increases and the amount of moisture collected by condensation increases. Therefore, by operating the cooling system 70 when the temperature is low, a larger amount of water can be collected and stored in the water tank 43 as circulating water.

  In this way, when a large amount of water is collected in the water tank 43 and excess circulating water that cannot be accommodated in the water tank 43 is discarded from the water disposal pipe 48, the circulating water in the water tank 43 is newly collected. Is replaced by water. Since the amount of impurities contained in the newly collected water is smaller than the amount of impurities contained in the circulating water that has been circulated repeatedly, the circulating water in the water tank 43 is newly collected. By substituting with, the impurities in the circulating water in the water tank 43 can be diluted to purify the water. Further, the impurity concentration can be kept low without performing special maintenance work. Thereby, circulating water with a low impurity concentration can be supplied to the fuel cell stack 11, and the performance degradation of the fuel cell stack 11 can be suppressed.

  In the present embodiment, a water waste adjusting valve 48a is disposed in the water waste conduit 48, and the ECU 81 controls the operation of the water waste adjusting valve 48a to adjust the amount of water to be discarded. The amount of circulating water stored in the water tank 43 and the dilution state of impurities can be adjusted. For example, when the circulating water in the water tank 43 reaches a predetermined amount or more, the water discarding adjustment valve 48 a may be opened to discard excess circulating water from the water discard pipe 48. The water waste pipe 48 is not necessarily connected to the water supply pipe 46, and may be connected to the condensed water discharge pipe 41 or directly to the water tank 43.

  In addition, when the temperature is low, such as in winter, the necessity of heating the interior of the vehicle increases. Therefore, the heat generated by the condenser 74 due to the operation of the cooling system 70 to dilute impurities in the circulating water in the water tank 43 is given to the air flowing through the heating air duct 82, so that the interior of the vehicle is It can be heated enough.

  Thus, in the present embodiment, the fuel cell system is a DWI-FC system that supplies water into the air supplied to the air flow path of the fuel cell stack 11, and is discharged from the fuel cell stack 11. Moisture in the air is condensed and removed by the condenser 14 cooled by the cooling system 70, and heat generated by the condenser 74, that is, waste heat of the cooling system 70, is used for heating the interior of the vehicle.

  Thereby, moisture can be efficiently collected and circulated and reused as circulating water supplied into the air supplied to the air flow path. Further, since the waste heat is used for heating the interior of the vehicle, energy efficiency can be improved. In particular, the water that is circulated by actively operating the cooling system 70 when the temperature is low increases the amount of recovered water and replaces the old circulating water with newly recovered water. The impurity concentration of can be reduced. Therefore, water with a low impurity concentration can be supplied to the fuel cell stack 11, and performance degradation of the fuel cell stack 11 can be suppressed.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is a figure which shows the structure of the fuel cell system in embodiment of this invention. It is a figure which shows the structure of the principal part of the fuel cell system in embodiment of this invention, and is the A section enlarged view in FIG. It is a figure which shows the structure of the system which controls the temperature of the air introduce | transduced in the room | chamber interior of the vehicle in embodiment of this invention.

Explanation of symbols

11 Fuel cell stack 14 Condenser 41 Condensate discharge line 42 Drain pump 43 Water tank 44 Water supply pump 45 Water filter 46 Water supply line 47 Water supply nozzle 48 Water waste line 70 Cooling system 71 Compressor 74 Condenser 79 Bypass refrigerant line 80 Heating System 82 Heating Air Duct 84 Cold Air Intake Line 85 Warm Air Discharge Line

Claims (5)

A fuel cell stack in which an electrolyte layer is sandwiched between a fuel electrode and an oxygen electrode, and is stacked with a separator having an air channel formed along the oxygen electrode;
A water supply nozzle for supplying water into the air supplied to the air flow path;
A condenser for condensing and removing moisture in the air discharged from the air flow path;
A water circulation system that collects water removed by the condenser and supplies the water to the water supply nozzle;
A refrigerant supply system for supplying refrigerant to the condenser;
A fuel cell system comprising: a heating system that recovers waste heat of the refrigerant supply system and heats the interior of the vehicle. The refrigerant supply system includes a compressor that compresses a gas-phase refrigerant, a condenser that liquefies the refrigerant compressed by the compressor, and an evaporator that vaporizes the liquefied refrigerant,
The evaporator is disposed in the condenser;
The fuel cell system according to claim 1, wherein the heating system uses heat of the condenser. The heating system has a heating air duct for introducing air that has passed through the condenser into a vehicle interior;
The heating air duct is connected to a cold air introduction line for selectively introducing cool air and a warm air discharge line for selectively discharging warm air, and selectively selects the gas-phase refrigerant discharged from the evaporator. The fuel cell system according to claim 2, wherein a warm air / cooling conduit passing through the fuel cell system is disposed. The water circulation system includes drainage means,
The fuel cell system according to claim 1, wherein the circulating water replaced by the water removed and recovered by the condenser is discharged from the drainage means. The water circulation system includes a water storage container for storing circulating water,
The fuel cell system according to claim 4, wherein when the amount of circulating water in the water storage container exceeds a predetermined amount, excess circulating water is discharged from the drainage means.

Images