JP5138889B2 - Fuel cell system - Google Patents

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 of an alkaline aqueous solution type (AFC), phosphoric acid type (PAFC), molten carbonate type (MCFC), solid oxide type (SOFC), direct methanol (DMFC), or the like. 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 thereof, hydrogen is decomposed into hydrogen ions (protons) and electrons, and the hydrogen ions are converted into a solid polymer electrolyte. Permeates 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 a fuel cell system, in order to warm up at the time of the cold etc., the technique which can heat a fuel cell with a heating means is proposed (for example, refer patent document 1).
Japanese Patent Laid-Open No. 2005-100654

  However, in the conventional fuel cell system, since the fuel cell itself is heated in a cold time or the like, no measures are taken for the fuel gas storage means even though the operation of the fuel cell can be improved. As a result, sufficient fuel gas cannot be supplied to the fuel cell. In particular, when the fuel gas storage means uses a hydrogen adsorbent or a hydrogen occlusion body, the ability of the hydrogen adsorber or hydrogen occlusion body to release hydrogen will be reduced at low temperatures, so that it may be used during cold weather. As a result, sufficient fuel gas cannot be supplied to the fuel cell.

  The present invention solves the problems of the conventional fuel cell system and heats a hydrogen gas storage body containing a hydrogen adsorber or a hydrogen occlusion body using waste heat, thereby generating a power generation amount of the fuel cell stack. It is an object of the present invention to provide a fuel cell system capable of stably supplying an amount of hydrogen gas corresponding to the above to the fuel cell stack and reducing the amount of power consumed by the auxiliary machinery.

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 laminated with a separator having a fuel flow path formed along the fuel electrode. A battery stack, a hydrogen adsorber or a hydrogen storage body, a hydrogen gas storage body that stores hydrogen gas supplied to the fuel flow path, a fuel cell cooling system that cools the fuel cell stack, and a vehicle air conditioner A refrigeration cycle cooling system for a machine or a vehicle freezer , each of the fuel cell cooling system and the refrigeration cycle cooling system including a conduit through which a refrigerant flows, and the conduit of the fuel cell cooling system and line of the refrigeration cycle cooling system, respectively, comprising a conduit and passes through non conduit passing through the hydrogen gas storage body, the refrigeration cycle type cooling system The waste heat to heat the hydrogen adsorbent or hydrogen storage material accommodated in the hydrogen gas reservoir.

  In another fuel cell system of the present invention, the fuel cell cooling system is further disposed so as to pass through a circulation pump for circulating the refrigerant, a radiator for cooling the refrigerant, and the hydrogen gas storage body, A first heating line through which the coolant that has cooled the fuel cell stack can selectively flow is provided.

  In still another fuel cell system of the present invention, the refrigeration cycle cooling system further includes a compressor that compresses a gas-phase refrigerant, a condenser that liquefies the refrigerant compressed by the compressor, and a liquefied refrigerant. An evaporator that is vaporized and a second heating pipe that is disposed so as to pass through the hydrogen gas storage body and into which the refrigerant compressed by the compressor can selectively flow.

According to the present invention, in a fuel cell system, a fuel cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxygen electrode is stacked with a separator having a fuel flow path formed along the fuel electrode. A battery stack, a hydrogen adsorber or a hydrogen storage body, a hydrogen gas storage body that stores hydrogen gas supplied to the fuel flow path, a fuel cell cooling system that cools the fuel cell stack, and a vehicle air conditioner A refrigeration cycle cooling system for a machine or a vehicle freezer , each of the fuel cell cooling system and the refrigeration cycle cooling system including a conduit through which a refrigerant flows, and the conduit of the fuel cell cooling system and of the refrigeration cycle cooling system conduit, respectively, provided with a conduit and does not pass through the conduit passes through the hydrogen gas storage body, the refrigeration cycle cooling system Heat by heating the hydrogen adsorbent is housed in the hydrogen gas reservoir or hydrogen absorbing material.

  In this case, heating means such as an electric heater is not required to heat the hydrogen adsorbent or the hydrogen storage body, so that the cost for disposing the heating means and the energy supplied to the heating means can be reduced. Therefore, the cost of the fuel cell system can be reduced, and the power consumption can be reduced.

  In another fuel cell system, the fuel cell cooling system is further disposed so as to pass through a circulation pump for circulating the refrigerant, a radiator for cooling the refrigerant, and the hydrogen gas storage body. A first heating line through which the refrigerant that has cooled the stack can selectively flow is provided.

  In this case, since the refrigerant is cooled by flowing through the first heating pipe, it is not necessary to increase the cooling capacity of the radiator. Therefore, the radiator can be reduced in size and weight, the cost can be reduced, and the entire fuel cell system can be reduced in size and weight. Furthermore, since the necessity to operate the cooling fan of the radiator is also reduced, the power consumption of the motor that drives the cooling fan can be reduced.

  Furthermore, even if the amount of heat required to heat the hydrogen adsorbent or hydrogen storage body increases, the waste heat generated by cooling the fuel cell stack increases, so a new heat source is required. Even if the fluctuation of the amount of heat required for heating the hydrogen adsorbent or the hydrogen occlusion material is wide (passed), the waste heat of the fuel cell cooling system can be used.

  In still another fuel cell system, the refrigeration cycle type cooling system further includes a compressor for compressing a gas-phase refrigerant, a condenser for liquefying the refrigerant compressed by the compressor, and an evaporator for vaporizing the liquefied refrigerant. And a second heating pipe that is arranged to pass through the hydrogen gas storage body and into which the refrigerant compressed by the compressor can selectively flow.

  In this case, since the refrigerant is cooled by flowing through the second heating pipeline, there is no need to increase the cooling capacity of the condenser. Therefore, the capacitor can be reduced in size and weight, the cost can be reduced, and the entire refrigeration cycle cooling system can be reduced in size and weight. Furthermore, since the necessity for operating the condenser cooling fan is also reduced, the power consumption of the motor driving the cooling fan can be reduced.

  Furthermore, when the load of the refrigeration cycle type cooling system increases and the required power increases, the amount of heat for heating the hydrogen gas storage body increases, and as a result, it is released from the hydrogen gas storage body and supplied to the fuel cell stack. As the amount of hydrogen generated increases, the output of the fuel cell stack automatically increases, and the required amount of power is automatically supplied to the refrigeration cycle cooling system.

  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.

  In the figure, reference numeral 11 denotes a fuel cell stack as a fuel cell (FC), 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 a fuel cell stack 11 as a power source and a secondary battery as a power storage means (not shown) in combination.

  The fuel cell stack 11 may be an alkaline aqueous solution type, phosphoric acid type, molten carbonate type, solid oxide type, 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 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 transmits 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 electrically connects the unit cells (MEA: MEMBRANE ELECTRODE ASSEMBLY) as a fuel cell and separates hydrogen gas as an anode gas and air introduced into the unit cells. The separator 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.

  The unit cell is composed of an air electrode as an oxygen electrode provided on the solid polymer electrolyte membrane side 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, an air electrode side collector as a net-like current collector in which a large number of apertures that pass through a mixed flow of air and water are collected in contact with the electrode diffusion layer on the air electrode side of the unit cell; It has 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, when fuel gas, that is, hydrogen gas as 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 water, resulting in a solid high Permeates through the molecular electrolyte membrane. Further, when the air electrode is used as a cathode electrode and an oxidant, that is, air as a cathode gas, is supplied into an oxygen chamber as an air flow path, oxygen in the air is combined with the hydrogen ions and electrons to form water. Is generated. 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 the oxygen chamber diffuses into the solid polymer electrolyte membrane and permeates into the fuel chamber through the solid polymer electrolyte membrane in the direction opposite to the hydrogen ions. It is a thing.

Reference numeral 12 denotes a hydrogen gas storage body which is a device for supplying hydrogen gas as fuel gas to the fuel cell stack 11. The hydrogen gas storage body 12 includes a hydrogen adsorber that adsorbs hydrogen such as activated carbon accommodated in a sealed container, or a hydrogen adsorber that stores hydrogen such as a hydrogen storage alloy. The hydrogen gas is supplied to the fuel cell stack 11 by releasing the hydrogen adsorbed on the hydrogen or the hydrogen occluded in the hydrogen occlusion body. The temperature T ₁ and the pressure P ₁ in the hydrogen gas storage body 12 are measured by the storage body temperature detector 13 and the storage body pressure detector 14. Since the hydrogen adsorber or the hydrogen occlusion body releases more hydrogen as the temperature is higher, the temperature T ₁ in the hydrogen gas storage body 12 is controlled to transfer the hydrogen gas storage body 12 to the fuel cell stack 11. The supply amount of hydrogen gas can be controlled.

  Reference numeral 20 denotes a fuel cell cooling system for cooling the fuel cell stack 11, which is a system for cooling the fuel cell stack 11 with a circulating refrigerant, as in a general cooling system for a vehicle internal combustion engine or the like. Here, 21 is a radiator as a radiator disposed in a refrigerant line 23 as a pipe through which the refrigerant flows, and heat exchange between the refrigerant and the outside air makes the heat of the refrigerant into the outside air. Dissipate heat to cool the refrigerant. The radiator 21 includes a cooling fan 22 driven by a motor (not shown). When the temperature of the refrigerant increases, the radiator 21 operates the cooling fan 22 as necessary to cool the refrigerant. Can be increased. In addition, although the said refrigerant | coolant is liquids, such as water and oil, what kind of refrigerant may be sufficient.

  The refrigerant pipe 23 is provided with a circulation pump 28 for circulating the refrigerant. The circulation pump 28 is driven by a motor (not shown). In addition, it demonstrates as a refrigerant | coolant circulating in the direction shown by the arrow in a figure.

  Further, a first heating pipe 24 is connected between the fuel cell stack 11 and the circulation pump 28 in the refrigerant pipe 23 so as to bypass a part of the refrigerant pipe 23. The first heating pipe line 24 is disposed so that at least a part thereof passes through the hydrogen gas storage body 12, and the refrigerant flowing out of the fuel cell stack 11 is selectively circulated so that the first heating pipe line 24 is provided in the hydrogen gas storage body 12. The hydrogen adsorber or the hydrogen occlusion body can be heated as necessary. Note that the inlet and outlet sides of the hydrogen gas storage body 12 in the first heating pipe 24 and the portion of the refrigerant pipe 23 bypassed by the first heating pipe 24 include a first flow rate adjustment valve 25, A second flow rate adjustment valve 26 and a third flow rate adjustment valve 27 are provided. Then, by operating the first flow rate adjustment valve 25, the second flow rate adjustment valve 26, and the third flow rate adjustment valve 27, the amount of refrigerant flowing through the first heating pipe line 24 can be adjusted.

The refrigerant pipe 23 has a first refrigerant temperature detector 31 for measuring the refrigerant temperature T ₂ immediately after flowing out of the fuel cell stack 11, and a _second refrigerant temperature T ₃ for measuring the refrigerant temperature T ₃ immediately before flowing into the radiator 21. A refrigerant temperature detector 32 and a third refrigerant temperature detector 33 that measures the refrigerant temperature T ₄ immediately before flowing into the fuel cell stack 11 are provided.

  Reference numeral 40 denotes a refrigeration cycle cooling system that uses a vapor compression refrigeration cycle arranged to cool a freezer (not shown) mounted on the vehicle. Here, the refrigeration cycle type cooling system 40 is a system similar to a refrigeration cycle used for general refrigerators, freezers, home air conditioners, vehicle air conditioners, and the like, for example, for cooling the interior of a vehicle. However, in the present embodiment, it will be described as a system for cooling the inside of a freezer mounted on a vehicle.

  Here, reference numeral 41 denotes a compressor as a compressor disposed in a refrigerant pipe 42 as a pipe through which the refrigerant flows, and compresses the gas-phase refrigerant. The refrigerant of the refrigeration cycle cooling system 40 is, for example, a so-called chlorofluorocarbon, which is a chlorofluorocarbon-like product that has been developed as a substitute for specific chlorofluorocarbons, but may be any type of refrigerant.

  Further, a condenser 43 as a refrigerant condenser is disposed on the downstream side of the compressor 41 with respect to the refrigerant flow direction in the refrigerant pipe 42. Then, the gas-phase refrigerant compressed to a high-temperature and high-pressure superheated gas state by the compressor 41 is liquefied by being cooled in the condenser 43 to be in a saturated liquid or supercooled liquid state. The compressor 41 is driven by a motor (not shown). The condenser 43 includes a cooling fan 44 that is driven by a motor (not shown). When the temperature of the refrigerant becomes high, the capacity of the refrigerant 43 is cooled by operating the cooling fan 44 as necessary. Can be increased.

  An expansion valve 45 is disposed on the downstream side of the condenser 43 with respect to the refrigerant flow direction in the refrigerant pipe 42. Further, an evaporator 46 as a refrigerant evaporator is disposed on the downstream side of the expansion valve 45 with respect to the refrigerant flow direction in the refrigerant pipe 42. The evaporator 46 is disposed in a freezer not shown. Then, the refrigerant in the state of the saturated liquid or the supercooled liquid passes through the expansion valve 45, is depressurized to the state of low-temperature and low-pressure wet steam, and flows into the evaporator 46. In the evaporator 46, the refrigerant absorbs heat from the air in the freezer and is again sucked into the compressor 41. Thereby, the air in a freezer is cooled and the stored matter in a freezer is further cooled. In addition, it demonstrates as a refrigerant | coolant circulating in the direction shown by the arrow in a figure.

  Further, a second heating pipe 47 is connected between the compressor 41 and the expansion valve 45 in the refrigerant pipe 42 so as to bypass the condenser 43. The second heating pipe 47 is disposed so that at least a part thereof passes through the hydrogen gas storage body 12, and selectively selects a gas-phase refrigerant compressed by the compressor 41 to a high-temperature and high-pressure superheated gas state. And is liquefied by being cooled in a portion in the hydrogen gas storage body 12 to be in a saturated liquid or supercooled liquid state. The hydrogen adsorbent or the hydrogen occlusion body can be heated by the heat released when the refrigerant is liquefied.

  Note that a fourth flow rate adjusting valve 48 and a fifth flow rate adjusting valve 49 are respectively provided on the inlet side and the outlet side of the hydrogen gas storage body 12 in the second heating pipe 47. Then, by operating the fourth flow rate adjustment valve 48 and the fifth flow rate adjustment valve 49, the amount of refrigerant flowing through the second heating pipe 47 can be adjusted. In this case, all the refrigerant discharged from the compressor 41 may flow into the second heating pipe 47 or only a part of the refrigerant may flow into the second heating pipe 47. Further, the ratio of the refrigerant flowing into the condenser 43 and the refrigerant flowing into the second heating pipe 47 may be adjusted.

In the present embodiment, the fuel cell system has an FC control ECU (Electronic Control Unit) (not shown) as a control device. The control device includes a calculation means such as a CPU and an MPU, a storage means such as a magnetic disk and a semiconductor memory, an input / output interface, etc., and a storage body temperature detector 13, a storage body pressure detector 14, a first refrigerant temperature detector. 31, the flow rate, temperature, etc. of hydrogen, oxygen, air, etc. supplied to the fuel flow path and the air flow path of the fuel cell stack 11 from various sensors including the second refrigerant temperature detector 32 and the third refrigerant temperature detector 33, By detecting the output voltage, the temperature T ₁ and pressure P ₁ in the hydrogen gas storage body 12, the temperature of the refrigerant, etc., the cooling fan 22, the circulation pump 28, the first flow rate adjustment valve 25, the second flow rate adjustment valve 26, Operations of the third flow rate adjustment valve 27, the compressor 41, the cooling fan 44, the fourth flow rate adjustment valve 48, the fifth flow rate adjustment valve 49, and the like are controlled. Further, the FC control ECU cooperates with other sensors provided in the vehicle and an EV (Electric Vehicle) control ECU (not shown) as a vehicle control means to supply fuel and oxidant to the fuel cell stack 11. Centrally control the operation of all equipment supplied.

  Then, the FC control ECU causes the refrigerant of the fuel cell cooling system 20 to flow into the first heating line 24 so that a necessary amount of hydrogen gas is supplied from the hydrogen gas storage body 12 to the fuel cell stack 11. The hydrogen adsorber or the hydrogen occlusion body in the hydrogen gas storage body 12 is heated by causing the refrigerant of the refrigeration cycle type cooling system 40 to flow into the second heating pipe 47.

  Next, the operation of the fuel cell system having the above configuration will be described.

  First, the operation when the refrigeration cycle cooling system 40 is not operated will be described. The case where the refrigeration cycle cooling system 40 is not operated is, for example, a case where a freezer mounted on a vehicle is not used. And in order to secure the necessary amount of hydrogen gas supplied from the hydrogen gas storage body 12 to the fuel cell stack 11, it is necessary to heat the hydrogen adsorbent or the hydrogen storage body in the hydrogen gas storage body 12 to release hydrogen. There is. Therefore, when the refrigeration cycle cooling system 40 is not operated, all of the heat energy required to heat the hydrogen adsorbent or the hydrogen occlusion body is covered by the waste heat of the fuel cell cooling system 20.

  First, in order to prevent the refrigerant of the refrigeration cycle type cooling system 40 from flowing through the second heating pipe 47, the FC control ECU closes the fourth flow rate adjustment valve 48 and the fifth flow rate adjustment valve 49 to set the second flow rate adjustment valve 49. The heating line 47 is shut off. Subsequently, the FC control ECU opens the first flow rate adjustment valve 25 and the second flow rate adjustment valve 26 so that the refrigerant of the fuel cell cooling system 20 flows through the first heating line 24. Further, the third flow rate adjusting valve 27 is closed. The amount of refrigerant flowing through the first heating pipe 24 can be adjusted by adjusting the time during which the third flow rate adjustment valve 27 is open, so the third flow rate adjustment valve 27 is intermittently closed. It can also be done.

Subsequently, the FC control ECU operates the circulation pump 28 to circulate the refrigerant of the fuel cell cooling system 20. When the operation of the fuel cell stack 11 is started, the refrigerant heated by cooling the fuel cell stack 11 circulates through the first heating pipe 24, and the hydrogen adsorbent or hydrogen in the hydrogen gas storage body 12. Heat the occlusion body. Accordingly, the temperature T ₁ of the hydrogen gas reservoir 12 is increased, the number of hydrogen released from the hydrogen adsorbent or hydrogen absorbing material.

In this case, the FC control ECU monitors the temperature T ₁ and the pressure P ₁ in the hydrogen gas storage body 12 measured by the storage body temperature detector 13 and the storage body pressure detector 14. Then, the temperature T ₁ and pressure P ₁ is and the type of the hydrogen adsorbent or hydrogen absorbing material, so as not to exceed the upper limit set by the specifications of the fuel cell system, the time open the third flow rate control valve 27 Is adjusted to adjust the amount of heat flowing into the hydrogen gas storage body 12. Further, the FC control ECU monitors the refrigerant temperature T ₃ immediately before flowing into the radiator 21 measured by the second refrigerant temperature detector 32. Then, by operating the cooling fan 22 as needed to adjust the cooling capacity of the refrigerant by the radiator 21, the refrigerant temperature T ₄ immediately before flowing into the fuel cell stack 11 measured by the third refrigerant temperature detector 33 is a refrigerant Do not exceed the upper temperature limit.

  Thus, since the hydrogen adsorber or the hydrogen occlusion body in the hydrogen gas storage body 12 is heated using the waste heat generated by cooling the fuel cell stack 11, no heating means such as an electric heater is required. Therefore, the cost for arranging the heating means and the energy supplied to the heating means can be reduced. Therefore, the cost of the fuel cell system can be reduced, and the power consumption can be reduced. In particular, when the fuel cell stack 11 is a so-called high-temperature solid polymer fuel cell that operates at a temperature of 100 [° C.] or higher, a sufficient amount of waste heat is generated, so the fuel cell cooling system 20 It is possible to heat the hydrogen adsorbent or the hydrogen occlusion body in the hydrogen gas storage body 12 only.

  Moreover, since the refrigerant is cooled by flowing through the first heating pipe 24, it is not necessary to increase the cooling capacity of the radiator 21. Therefore, the radiator 21 can be reduced in size and weight, the cost can be reduced, and the entire fuel cell system can be reduced in size and weight. Furthermore, since the necessity for operating the cooling fan 22 is also reduced, the power consumption of the motor that drives the cooling fan 22 can be reduced.

  Furthermore, even if the amount of heat required to heat the hydrogen adsorber or the hydrogen occlusion body in the hydrogen gas storage body 12 increases, the waste heat generated by cooling the fuel cell stack 11 increases. There is no need for a new heat source. This is because when the hydrogen adsorbent or the hydrogen storage body is further heated, more hydrogen is released from the hydrogen adsorbent or the hydrogen storage body and supplied to the fuel cell stack 11, so that the fuel cell stack 11 is cooled. This is because the waste heat generated by this increases. Therefore, even if the variation in the amount of heat required to heat the hydrogen adsorbent or the hydrogen occlusion body is in a wide range, the waste heat of the fuel cell cooling system 20 can cope with it.

  Next, the operation for operating the refrigeration cycle cooling system 40 will be described.

  FIG. 2 is a diagram showing the relationship between the required power amount of the cooling system and the amount of heat used to release an amount of hydrogen corresponding to the required power amount in the embodiment of the present invention.

  When the refrigeration cycle type cooling system 40 is operated to use a freezer mounted on a vehicle, all of the thermal energy necessary for heating the hydrogen adsorber or the hydrogen occlusion body in the hydrogen gas storage body 12 is obtained. The waste heat of the refrigeration cycle type cooling system 40 is covered. Since the fuel cell system operates, the fuel cell cooling system 20 operates to cool the fuel cell stack 11 with the refrigerant.

  First, in order to allow the refrigerant of the refrigeration cycle type cooling system 40 to flow through the second heating pipe 47, the FC control ECU opens the second flow rate adjustment valve 48 and the fifth flow rate adjustment valve 49 to open the second flow rate adjustment valve 49. The heating line 47 is connected. In this case, the fourth flow rate adjusting valve 48 and the fifth flow rate adjusting valve 49 are left open. The amount of refrigerant flowing through the second heating pipe 47 can be adjusted by adjusting the time during which the fourth flow rate adjustment valve 48 and the fifth flow rate adjustment valve 49 are open. The adjustment valve 48 and the fifth flow rate adjustment valve 49 may be closed intermittently.

Subsequently, the FC control ECU closes the first flow rate adjustment valve 25 and the second flow rate adjustment valve 26, and the refrigerant of the fuel cell cooling system 20 blocks the first heating pipeline 24. Further, the third flow rate adjusting valve 27 is opened, and the circulation pump 28 is operated to circulate the refrigerant of the fuel cell cooling system 20. When the operation of the fuel cell stack 11 is started, the refrigerant heated by cooling the fuel cell stack 11 circulates through the refrigerant line 23 without passing through the first heating line 24. Thereby, the refrigerant is cooled by passing through the radiator 21. In this case, the FC control ECU monitors the refrigerant temperature T ₃ immediately before flowing into the radiator 21 measured by the second refrigerant temperature detector 32. Then, if necessary, the cooling fan 22 is operated to adjust the cooling capacity of the refrigerant by the radiator 21, and the refrigerant temperature T ₄ immediately before flowing into the fuel cell stack 11 measured by the third refrigerant temperature detector 33 is the refrigerant. Do not exceed the upper temperature limit.

Further, the FC control ECU operates the compressor 41 to circulate the refrigerant of the refrigeration cycle type cooling system 40. Then, the gas-phase refrigerant compressed to the state of the high-temperature and high-pressure superheated gas by the compressor 41 flows into the second heating pipe 47 and is liquefied by being cooled in the portion inside the hydrogen gas storage body 12. , A saturated liquid or a supercooled liquid. Then, the hydrogen adsorbent or the hydrogen occlusion body is heated by the heat released when the refrigerant is liquefied. Accordingly, the temperature T ₁ of the hydrogen gas reservoir 12 is increased, the number of hydrogen released from the hydrogen adsorbent or hydrogen absorbing material.

In this case, the FC control ECU monitors the temperature T ₁ and the pressure P ₁ in the hydrogen gas storage body 12 measured by the storage body temperature detector 13 and the storage body pressure detector 14. Then, the fourth flow rate adjustment valve 48 and the fifth flow rate adjustment are performed so that the temperature T ₁ and the pressure P ₁ do not exceed the upper limit values set according to the type of the hydrogen adsorbent or the hydrogen storage unit and the specifications of the fuel cell system. The amount of heat flowing into the hydrogen gas storage body 12 is adjusted by adjusting the time during which the valve 49 is open.

  Then, the refrigerant that has become a saturated liquid or supercooled liquid state by passing through the second heating pipe 47 is decompressed to a low-temperature and low-pressure wet steam state by passing through the expansion valve 45, and the evaporator 46. Flows in. In the evaporator 46, the refrigerant absorbs heat from the air in the freezer and is again sucked into the compressor 41. Thereby, the air in a freezer is cooled and the stored matter in a freezer is further cooled.

  Thus, in order to heat the hydrogen adsorbent or the hydrogen occlusion body in the hydrogen gas storage body 12 using the waste heat generated by cooling the inside of the freezer, no heating means such as an electric heater is required. The cost for disposing the heating means and the energy supplied to the heating means can be reduced. Therefore, the cost of the fuel cell system can be reduced, and the power consumption can be reduced.

  Further, since the refrigerant of the refrigeration cycle type cooling system 40 is cooled by flowing through the second heating pipe 47, it is not necessary to increase the cooling capacity of the condenser 43. Therefore, the condenser 43 can be reduced in size and weight, the cost can be reduced, and the entire refrigeration cycle cooling system 40 can be reduced in size and weight. Furthermore, since the necessity for operating the cooling fan 44 is also reduced, the power consumption of the motor that drives the cooling fan 44 can be reduced.

  Further, when the load of the refrigeration cycle type cooling system 40 increases and the required electric energy increases, the output of the fuel cell stack 11 automatically increases, and the necessary electric energy is automatically supplied to the refrigeration cycle type cooling system. 40.

  For example, when the inside of the freezer is cooled to a lower temperature, or when stored items are frequently taken in and out and more outside air flows into the freezer, the refrigerant generates more heat from the air in the freezer at the evaporator 46. Since it is necessary to absorb, the load of the compressor 41 increases in order to circulate more refrigerant. Therefore, the amount of electric power necessary for driving the compressor 41 increases, and as a result, the required electric energy of the entire refrigeration cycle cooling system 40 increases. On the other hand, when more refrigerant is circulated, the amount of heat released from the refrigerant passing through the second heating pipe 47 is increased, and the hydrogen adsorbent or hydrogen occlusion body in the hydrogen gas storage body 12 is further heated. Therefore, more hydrogen is discharged from the hydrogen adsorber or the hydrogen storage body and supplied to the fuel cell stack 11, so that the output of the fuel cell stack 11 is further increased and a larger amount of electric power is supplied to the refrigeration cycle cooling system. 40.

  As a result of experiments conducted by the inventor of the present invention, the required power amount of the refrigeration cycle type cooling system 40 and the heat amount necessary for releasing hydrogen corresponding to the required power amount from the hydrogen gas storage body 12 It was found that there is a relationship as shown in FIG. In FIG. 2, the horizontal axis represents the required power amount of the refrigeration cycle cooling system 40, and the vertical axis represents the amount of heat used to release a corresponding amount of hydrogen. In this experiment, a hydrogen gas storage body 12 containing a hydrogen storage body such as a hydrogen storage alloy was used. From this, when the load of the refrigeration cycle cooling system 40 increases and the required power amount increases, the amount of heat for heating the inside of the hydrogen gas storage body 12 increases, and as a result, is released from the hydrogen gas storage body 12. As a result, the amount of hydrogen supplied to the fuel cell stack 11 increases, the output of the fuel cell stack 11 automatically increases, and the required amount of power is automatically supplied to the refrigeration cycle cooling system 40. I understand.

  Thus, in this Embodiment, a fuel cell system heats using the waste heat of the hydrogen gas storage body 12 which accommodates a hydrogen adsorption body or a hydrogen storage body. Therefore, the output of the fuel cell stack 11, that is, an amount of hydrogen gas corresponding to the amount of power generation can be stably supplied to the fuel cell stack 11. Further, since no heating means such as an electric heater for heating the fuel cell stack 11 is required, the power consumption can be reduced. Furthermore, the amount of power consumed by the auxiliary machines such as the cooling fans 22 and 44 can be reduced.

  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 relationship between the electric energy required in order to discharge | release the amount of hydrogen corresponding to the required electric energy of the cooling system in embodiment of this invention corresponding to this required electric energy.

Explanation of symbols

11 Fuel Cell Stack 12 Hydrogen Gas Storage Body 20 Fuel Cell Cooling System 21 Radiator 24 First Heating Line 28 Circulating Pump 40 Refrigeration Cycle Cooling System 41 Compressor 43 Condenser 46 Evaporator 47 Second Heating Line

Claims (3)

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 a fuel flow path formed along the fuel electrode;
A hydrogen gas storage body that contains a hydrogen adsorbent or a hydrogen storage body and stores hydrogen gas supplied to the fuel flow path;
A fuel cell cooling system for cooling the fuel cell stack;
A refrigeration cycle cooling system for a vehicle air conditioner or a vehicle freezer,
Each of the fuel cell cooling system and the refrigeration cycle cooling system includes a conduit through which a refrigerant flows,
The fuel cell cooling system pipe and the refrigeration cycle cooling system pipe each include a pipe passing through the hydrogen gas storage body and a pipe passing through the hydrogen gas storage body, respectively.
A fuel cell system, wherein a hydrogen adsorber or a hydrogen occlusion body accommodated in the hydrogen gas storage body is heated by waste heat of the refrigeration cycle cooling system.   The fuel cell cooling system is disposed so as to pass through a circulation pump for circulating the refrigerant, a radiator for cooling the refrigerant, and the hydrogen gas storage body, and the refrigerant that has cooled the fuel cell stack selectively flows in The fuel cell system according to claim 1, comprising a possible first heating line.   The refrigeration cycle cooling system passes through a compressor that compresses a gas-phase refrigerant, a condenser that liquefies the refrigerant compressed by the compressor, an evaporator that vaporizes the liquefied refrigerant, and the hydrogen gas storage body. 2. The fuel cell system according to claim 1, further comprising a second heating pipe line that is arranged as described above and into which the refrigerant compressed by the compressor can selectively flow.

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