JP5417988B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system.

  The fuel cell system includes a housing having a housing chamber for housing the fuel cell, a gas sensor for detecting a gas concentration in the housing chamber of the housing, and a ventilation unit for ventilating the inside of the housing chamber. Even if a gas leak is detected by a gas sensor in the storage room, it can be dealt with by ventilation in the storage room (Patent Document 1). Furthermore, in other documents, a fuel cell system is disclosed in which a gas sensor for detecting gas is provided in a housing chamber of a housing that houses a fuel cell (Patent Documents 2 and 3). Also disclosed is a fuel cell system that suppresses an increase in the concentration of combustible gas in the storage chamber by increasing the opening of the automatic release door of the storage chamber to increase the ventilation volume when the detected combustible gas concentration increases. (Patent Document 4).

JP 2006-128138 A JP 2004-253259 A JP 2006-196265 A JP-A-8-31436

  According to the fuel cell system described above, since the gas sensor is provided, even if a gas leak occurs, the gas leak can be detected well.

  The present invention has been made to further improve the reliability of gas leak detection, and provides a fuel cell system that is advantageous for detecting gas leaks in a storage chamber regardless of changes in the ventilation volume of the storage chamber. The task is to do.

A fuel cell system according to the present invention includes a fuel cell having an anode to which an anode fluid is supplied and a cathode to which a cathode fluid is supplied, a housing having a housing chamber for housing the fuel cell, and a housing chamber for the housing. A gas ventilation unit that ventilates the interior, a gas sensor that detects gas leakage of fuel raw material gas or anode fluid in the housing chamber of the housing, and a gas that is judged to be gas leakage when the concentration of gas detected by the gas sensor is higher than a reference concentration It has a determination unit that executes leakage determination processing and a temperature sensor that detects the temperature of the storage chamber. The ventilation unit detects when the temperature of the storage chamber detected by the temperature sensor is relatively high. Compared to the case where the temperature of the storage room is relatively low, the ventilation amount V of the storage room is increased to suppress fluctuations in the temperature of the storage room. big In some cases, the reference concentration in the gas leak determination process is lowered as compared with when the ventilation volume V of the storage room is relatively small, and the reference concentration in the gas leak determination process is continuously set according to the ventilation volume V of the storage room. Or , it is changed stepwise by 3 or more values .

  Therefore, according to the fuel cell system of the present invention, it is advantageous to detect gas leakage well even when the ventilation volume of the storage chamber is large or when the ventilation volume of the storage chamber is small.

  Here, the anode of the fuel cell is a portion to which an anode fluid is supplied. The cathode of the fuel cell is the part where the cathode fluid is supplied. The housing has a storage chamber for storing the fuel cell. The ventilation unit ventilates the inside of the housing chamber of the housing. The gas sensor detects gas leakage in the housing chamber of the housing. When the reformer is provided in the system, the gas leaked in the storage chamber includes a fuel raw material gas that becomes an anode gas fluid and / or an anode fluid that is reformed from the fuel raw material gas. When the reformer is not provided in the system, the gas leaked in the storage chamber includes an anode fluid supplied to the anode of the fuel cell. Examples of the anode fluid include hydrogen gas and hydrogen-containing gas.

  According to the fuel cell system of the present invention, the determination unit changes the reference concentration in the gas leak determination process according to the ventilation amount of the storage chamber. Therefore, according to the fuel cell system of the present invention, it is advantageous for detecting gas leakage in the storage chamber satisfactorily even when the ventilation volume of the storage chamber is large or when the ventilation volume of the storage chamber is small. Become.

It is a figure which shows a fuel cell system. It is a graph which shows the relationship between the ventilation volume of a storage chamber, and the reference | standard density | concentration in a gas leak determination process. It is a graph which shows the relationship between the ventilation volume of a storage chamber, and the reference | standard density | concentration in a gas leak determination process. It is a flowchart which shows the control law which a control part performs. It is a flowchart which shows the control law of another example which a control part performs. It is a figure which concerns on other embodiment and shows a fuel cell system.

  According to one aspect of the present invention, the determination unit reduces the reference concentration in the gas leakage determination process when the ventilation volume of the storage room is relatively large, compared to when the ventilation volume of the storage room is relatively small. It is preferable to make it. When the ventilation volume of the storage room is relatively large, the flow rate of ventilation air exhausted from the storage room to the outside increases and the flow rate of ventilation air entering the storage room increases. For this reason, even if a gas leak has occurred in the containment chamber, the dilution rate by which the leaked gas is diluted by the ventilation air that has entered the containment chamber becomes high, and the determination unit can detect the gas leak well. It may not be possible. In this case, when the ventilation volume of the storage room is relatively large, it is preferable that the determination unit lowers the reference concentration of the gas leak determination compared to when the ventilation volume of the storage room is relatively small.

  Depending on the location of the gas sensor in the storage chamber for detecting gas leakage, the material of the gas sensor, the structure of the gas sensor, the response sensitivity of the gas sensor, etc., the sensitivity of the gas sensor may fluctuate when the ventilation volume of the storage chamber is relatively large. is there. Therefore, the determination unit can increase the reference concentration in the gas leakage determination process when the ventilation volume of the storage chamber is relatively large, compared to when the ventilation volume of the storage chamber is relatively small.

  According to one aspect of the present invention, it is preferable that a temperature sensor for detecting the temperature of the storage chamber is provided. The ventilation unit increases the ventilation amount in the storage room when the temperature of the storage room detected by the temperature sensor is relatively high, compared to when the temperature of the storage room detected by the temperature sensor is relatively low. It is preferable to suppress fluctuations in the chamber temperature. For example, it is preferable that the ventilation unit relatively increases the ventilation amount in the accommodation room as the temperature of the accommodation room detected by the temperature sensor becomes relatively high, and suppresses the excessive increase in the temperature of the accommodation room.

(Embodiment 1)
FIG. 1 shows the concept of the first embodiment. The fuel cell system is a system in which a polymer electrolyte fuel cell is assembled. The fuel cell system includes a housing 1 having a storage chamber 10, a combustion unit 2 that is a burner that burns flammable fuel with air, and an air supply device 3 such as a pump and a blower that supplies air to the combustion unit 2. And a reforming device 4 for reforming the reforming fuel by heating based on the combustion unit 2 and a ventilation unit 6 for generating a ventilation flow for ventilating the storage chamber 10.

  A housing chamber 10 of the housing 1 houses a combustion unit 2, an air supply device 3, a reforming device 4, a ventilation unit 6, and a stack 7. A combustion fuel passage 20 for supplying combustion fuel having combustibility to the combustion unit 2 is disposed in the storage chamber 10. A reforming fuel passage 40 for supplying the reforming fuel to the reforming device 4 is disposed in the storage chamber 10. The air supply device 3 has a suction port 31 for sucking air in the storage chamber 10 and an air supply mechanism 32. The suction port 31 faces the storage chamber 10. Here, when the air supply mechanism 32 built in the air supply device 3 operates and rotates, the air in the storage chamber 10 is sucked from the suction port 31 and is burned as air for combustion via the air supply passage 34. And used for the combustion reaction in the combustion section 2. The combustion fuel and reforming fuel are preferably gaseous. The stack 7 is configured by stacking a plurality of fuel cell single cells.

  As shown in FIG. 1, a single cell constituting the stack 7 includes an anode 7a, a cathode 7c, and a solid polymer electrolyte 7e sandwiched between the anode 7a and the cathode 7c. A cathode gas passage 70 extends from the cathode 7 c of the stack 7. In the cathode gas passage 70, a humidifier 71 for humidifying the cathode gas (cathode gas fluid), and a cathode for supplying the air in the storage chamber 10 to the cathode 7c of the stack 7 via the humidifier 71 as the cathode gas (cathode fluid). A gas pump 72 (cathode fluid carrier source) is provided. In addition, since the air (cathode gas) in the storage chamber 10 is warmed by heat radiation from the reformer 4 and the stack 7, the efficiency of the power generation reaction is increased. The cathode offgas that has finished the power generation reaction at the cathode 7 c of the stack 7 is discharged from the cathode offgas discharge port 74 to the outside 14 via the cathode offgas passage 73 disposed in the storage chamber 10.

  As shown in FIG. 1, the housing 1 has a box shape and includes at least a ceiling wall 1u, a bottom wall 1d, a first side wall 1e, and a second side wall 1f. In the lower part of the first side wall 1e, an intake port 11 is formed as a ventilation port so that outside air can be sucked into the lower part of the storage chamber 10. An exhaust port 12 is formed in the upper part of the second side wall 1f as a ventilation port so that the air in the upper part of the storage chamber 10 can be discharged to the outside 14.

  The ventilation unit 6 includes a ventilation blade 60 and a drive unit 62 formed by a drive motor that rotationally drives the ventilation blade 60, and faces the intake port 11 of the housing 1 directly or through another member. The air in the outside 14 is easily sucked into the storage chamber 10. When the ventilation unit 6 is activated and the ventilation blades 60 are rotated, the air in the outside 14 of the housing 1 passes through the filter 17 from the intake port 11 of the housing 1 and is sucked into the storage chamber 10 in the direction of the arrow X1, Furthermore, it flows through the storage chamber 10 and is discharged from the exhaust port 12 to the outside 14 of the housing 1 in the direction of the arrow X2. Thereby, ventilation of the storage chamber 10 is performed.

  As shown in FIG. 1, the air supply device 3 is disposed inside the housing 1 with respect to the air inlet 11 and the ventilation unit 6 of the housing 1. Therefore, the suction port 31 of the air supply device 3 is disposed inside the housing 1 with respect to the intake port 11 and the ventilation unit 6 of the housing 1. For this reason, when the ventilation unit 6 is activated and fresh air in the outside 14 is sucked into the storage chamber 10 in the direction of the arrow X1, fresh air having a high oxygen concentration is satisfactorily sucked into the air supply device 3 from the suction port 31. Can do. In this case, the combustion efficiency in the combustion part 2 becomes high. The intake port 11 is provided with a purification filter 17 for reducing dust and the like contained in the outside air flowing into the storage chamber 10 from the intake port 11. The filter 17 is generally equipped, but may be abolished when the outside air is clean.

  In general, when the fuel cell system is in operation, the ventilation unit 6 operates to ventilate the air in the storage chamber 10 as described above. For this reason, even if a gas leak occurs in the storage chamber 10 due to the looseness of the piping or the like, the leaked gas is immediately discharged from the exhaust port 12 to the outside 14 by the ventilation action of the ventilation unit 6. Therefore, safety is improved.

  A water supply passage 44 is extended in the reformer 4. The water supply passage 44 stores a raw water such as condensed water generated by the system and a purifier 45 for purifying the raw water (for example, condensed water, tap water, etc. generated in the system) with a purification material 45a such as an ion exchange resin. And a tank 46 for storing high-purity water purified by the purifier 45 as reforming water. When the water supply pump 48 (water conveyance source) is activated, the water in the tank 46 is supplied as reformed water to the evaporation section of the reformer 4 through the water supply passage 44 and is vaporized. The generated steam is supplied to the reforming unit of the reformer 4. Further, the steam reforms the fuel material supplied from the reforming fuel passage 40 to the reformer 4.

  When the fuel cell system is operated, combustible combustion fuel is supplied to the combustion unit 2 through the combustion fuel passage 20. Further, since the air supply device 3 operates, the air in the storage chamber 10 is supplied as combustion air from the suction port 31 of the air supply device 3 to the combustion unit 2 through the air supply passage 34. As a result, the combustion fuel is burned by the combustion air in the combustion section 2. Thus, the air in the storage chamber 10 is supplied to the combustion unit 2 as combustion air. Here, during the operation of the system, the air in the storage chamber 10 is warmed by heat radiation from the reformer 4 and the stack 7, so that the combustion efficiency in the combustion unit 2 is increased.

  As described above, since the combustion fuel is burned in the combustion section 2, the reforming section of the reformer 4 is heated to a high temperature so as to be suitable for the reforming reaction. In this state, reforming fuel is supplied from the reforming fuel passage 40 to the reforming device 4, and water stored in the tank 46 is supplied as reforming water to the evaporation section of the reforming device 4. Steamed. The generated steam reforms the reforming fuel in the reforming section of the reformer 4. As a result, anode gas mainly containing hydrogen is generated. The produced anode gas is supplied to the anode 7a of the stack 7 through the anode gas passage 78 and the inlet valve 79i, and used for power generation reaction. Since the anode off-gas that has undergone the power generation reaction retains a combustible component such as hydrogen, it is supplied from the outlet of the anode 7 a to the combustion unit 2 through the outlet valve 79 p and the anode off-gas passage 77 and burned in the combustion unit 2. The combustion exhaust gas is discharged from the exhaust port (not shown) of the combustion unit 2 to the outside 14. The anode inlet of the stack 7 can be opened and closed by an inlet valve 79i. The outlet of the anode 7a can be opened and closed by an outlet valve 79p.

  During the power generation operation of the system, the cathode gas pump 72 (cathode fluid conveyance source) operates, so that the air in the storage chamber 10 is supplied as cathode gas (cathode fluid) from the inlet 72i to the cathode 7c of the stack 7 via the humidifier 71. The When the fuel cell system is operated in this manner, the ventilation unit 6 is activated and the ventilation blades 60 are rotated, and a suction action is generated on the intake port 11 side of the ventilation unit 6. For this reason, air in the outside 14 of the housing 1 is sucked into the storage chamber 10 from the intake port 11 of the housing 1 in the direction of the arrow X1, flows through the storage chamber 10, and flows from the exhaust port 12 toward the direction of the arrow X2. It is discharged to the outside 14 of. Thereby, ventilation of the storage chamber 10 is performed.

  A gas leak sensor 100 m (gas sensor) is disposed in the upper portion of the storage chamber 10. In particular, a gas leak sensor 100m is disposed near the exhaust port 12 in the upper part of the housing chamber 10. In the unlikely event that a gas leak occurs due to loosening of the piping in the storage chamber 10, the gas leak is detected by the gas leak sensor 100m. A temperature sensor 100 t is disposed on the upper part of the storage chamber 10. In particular, a temperature sensor 100 t is disposed near the exhaust port 12 in the upper part of the storage chamber 10.

  According to the present embodiment, the control unit 100 functioning as a determination unit performs gas leakage determination processing for determining gas leakage in the storage chamber 10 during operation such as system start-up operation, power generation operation, and stop operation. . When the gas concentration detected by the gas leak sensor 100m is higher than the reference concentration in the gas leak determination process, the control unit 100 determines that the gas leaks, and notifies the alarm device 110 of the alarm signal Ar, and the alarm device 110 generates an alarm. To emit. Here, examples of the gas to be leaked include a reforming fuel used as a raw material for the anode gas and / or an anode gas obtained by reforming the reforming fuel. Cathode gas is air and has no real harm, so it is not subject to gas leakage.

  In the gas leak determination process described above, the control unit 100 changes the reference concentration in the gas leak determination process according to the ventilation amount V of the storage chamber 10. In particular, the control unit 100 reduces the reference concentration in the gas leak determination process when the ventilation amount V of the storage chamber 10 is relatively large compared to when the ventilation amount V of the storage chamber 10 is relatively small. . The reason is as follows. That is, when the ventilation volume V of the storage chamber 10 is relatively large, the flow rate of ventilation air exhausted to the outside from the exhaust port 12 of the storage chamber 10 increases and enters the storage chamber 10 from the intake port 11. Increases ventilation air flow. For this reason, even if a gas leak has occurred in the storage chamber 10, the dilution rate at which the gas leaked in the storage chamber 10 is diluted with the air for ventilation is high. In this case, the gas leak sensor 100m detects the concentration of the gas diluted with the air for ventilation. As a result, the control unit 100 may not be able to detect a gas leak despite the occurrence of a gas leak in the storage chamber 10.

  Therefore, according to the present embodiment, the control unit 100 is configured such that when the ventilation volume V of the storage chamber 10 is relatively large, the control unit 100 is compared with when the ventilation volume V of the storage chamber 10 is relatively small. Reduce the reference concentration in the gas leak determination process. For this reason, when a gas leak has occurred in the storage chamber 10, the control unit 100 can detect a gas leak in the storage chamber 10 even if the dilution rate at which the leaked gas is diluted increases.

  FIG. 2 shows an example of a map stored in a predetermined area of a storage element (memory) 100 c mounted on the control unit 100. According to this map, the relationship between the ventilation volume V of the storage chamber 10 and the reference concentration in the gas leakage determination process is defined. That is, during the operation of the system, when the ventilation amount V of the storage chamber 10 is relatively large, the reference concentration in the gas leak determination process is lowered, and when the ventilation amount V of the storage chamber 10 is relatively small, the gas leak The reference density in the determination process is increased. Specifically, when the ventilation amount V of the storage chamber 10 is V2 (V1 <V2) and is relatively large, the reference concentration in the gas leak determination process is lowered and set to the concentration C2.

  On the other hand, when the ventilation amount V of the storage chamber 10 is V1 and is relatively small, the reference concentration in the gas leakage determination process is increased and set to the concentration C1 (C1> C2). That is, as the ventilation volume V increases from V1 to V2, the reference concentration is continuously decreased from the concentration C1 to the concentration C2 along the characteristic line CA. V1 indicates the minimum value of the ventilation volume V of the system. V2 indicates the maximum value of the ventilation volume V of the system. In other words, as can be understood from the characteristic line CA in FIG. 2, the gas leak is diluted by the ventilation air as the ventilation amount V of the storage chamber 10 increases, so that the reference concentration in the gas leak determination process of the gas leak To improve the gas leak detection sensitivity.

  FIG. 3 shows another example of the map. Also in this map, when the ventilation amount V of the storage chamber 10 is relatively large, the reference concentration in the gas leak determination processing is lowered, and when the ventilation amount V of the storage chamber 10 is relatively small, the gas leak determination processing is performed. The reference concentration is increased. That is, the reference concentration in the gas leak determination process is gradually reduced from C1 to C2 along the characteristic line CB as the ventilation amount V of the storage chamber 10 increases from V1 to V2. Note that instead of the map, arithmetic expressions corresponding to the characteristic lines CA and CB may be stored in the storage element 100c of the control unit 100, and the reference concentration may be obtained from the ventilation amount V based on the arithmetic expression.

  FIG. 4 shows an example of a control rule executed by the control unit 100. The control law is not limited to this. As shown in FIG. 4, the control unit 100 reads system information (step S102) and detects the current ventilation amount V (step S104). In this case, the control unit 100 can read the output (the number of rotations per unit time) of the drive unit 62 of the ventilation unit 6 and detect the current ventilation amount V based on the output of the drive unit 62. Based on the detected current ventilation volume V, the control unit 100 extracts a reference concentration from a map stored in a predetermined area of the storage element 100c such as a memory (step S106), and the extracted concentration is used as a gas leak. The reference density is determined in the determination process (step S108).

  Here, in the gas leakage determination process, when the concentration of the gas detected by the gas leakage sensor 100m is larger than the reference concentration, the control unit 100 determines that the gas is leaking and notifies the alarm device 110 of the alarm signal Ar. As a result, the alarm device 110 issues an alarm. In order to prevent hunting, the control unit 100 waits for a predetermined time (step S10), and then returns to (step S) 102.

  The control unit 100 obtains the ventilation amount V of the storage chamber 10 in step S104. In this case, as the ventilation amount V of the storage chamber 10, the ventilation amount V may be obtained based on the number of rotations (output) per unit time of the drive unit 62 of the ventilation unit 6, or before and after the ventilation unit 6. The ventilation amount V may be obtained based on the differential pressure. Or the control part 100 may provide the flow rate sensor which detects the ventilation flow volume by the ventilation part 6, and may obtain | require the ventilation volume V based on the ventilation flow volume which a flow rate sensor detects.

(Embodiment 2)
Since this embodiment basically has the same configuration and the same function and effect as the first embodiment, FIGS. 1 to 4 are applied mutatis mutandis. According to the present embodiment, as shown in FIG. 1, a temperature sensor 100 t is provided as a temperature sensor that detects the temperature of the storage chamber 10. When heat accumulation occurs in the storage chamber 10, the temperature of the storage chamber 10 becomes excessively high, and there is a possibility that the life of the auxiliary equipment of the system disposed in the storage chamber 10 may be reduced. In particular, the life of the refining material 45a formed of an ion exchange resin or the like may be reduced. On the other hand, when the temperature in the storage chamber 10 becomes excessively low, the temperature of the stack 7 is excessively decreased, the power generation efficiency is decreased, and the exhaust heat recovery efficiency of the system may be decreased. Furthermore, there is a risk of freezing in the piping.

  In consideration of such circumstances, the control unit 100 performs control to suppress a large variation in the internal temperature T of the storage chamber 10. That is, when the system is operated in summer or in a tropical region, or when the system is operated for a long time with an excessively high power output state, the temperature of the storage chamber 10 detected by the temperature sensor 100t is excessive. May be high. In such a case, in order to suppress heat accumulation in the storage chamber 10, the control unit 100 relatively increases the number of rotations per unit time of the drive unit 62 of the ventilation unit 6 (output of the ventilation unit 6), The amount of air entering the storage chamber 10 from the intake port 11 is increased, and the amount of air discharged from the exhaust port 12 to the outside 14 is increased. Thereby, the ventilation amount V of the storage chamber 10 is relatively increased, and an excessive increase in the temperature of the storage chamber 10 is suppressed.

  In addition, when the system is operated in winter or in a cold region, the internal temperature T of the storage chamber 10 detected by the temperature sensor 100t may be excessively low when the power generation output of the system is low. In such a case, the control unit 100 relatively reduces the number of rotations per unit time of the drive unit 62 of the ventilation unit 6 (output of the drive unit 62), and enters the storage chamber 10 from the intake port 11. The amount of air discharged from the exhaust port 12 to the outside 14 is relatively decreased while the amount is relatively decreased. Thereby, the ventilation amount V of the storage chamber 10 is relatively decreased, and an excessive decrease in the internal temperature T of the storage chamber 10 is suppressed. Thereby, excessively high temperature and excessively low temperature of the internal temperature T of the storage chamber 10 are suppressed, and freezing is suppressed. As described above, according to the present embodiment, the ventilation amount V is changed by the ventilation unit 6 according to the internal temperature T of the storage chamber 10 in order to suppress a large change in the internal temperature T of the storage chamber 10.

  As described above, according to the present embodiment, the ventilation amount V is changed by the ventilation unit 6 based on the internal temperature T of the storage chamber 10. Here, when the ventilation amount V of the storage chamber 10 is relatively large, the control unit 100 compares the control unit 100 with FIGS. 2 and 3 in comparison with when the ventilation amount V of the storage chamber 10 is relatively small. On the basis of the characteristic lines CA and CB shown in FIG. For this reason, in the unlikely event that a gas leak has occurred in the storage chamber 10, even if the dilution rate at which the leaked gas is diluted by ventilation increases, the control unit 100 performs the storage chamber 10 in the gas leak determination process. It is possible to detect a gas leak in the well.

(Embodiment 3)
FIG. 5 shows a third embodiment. Since this embodiment basically has the same configuration and the same function and effect as those of the first embodiment, FIGS. 1 to 3 apply mutatis mutandis. The housing 1 includes an intake port 11 that functions as a ventilation port communicating with the storage chamber 10, and an air purification filter 17 provided in the intake port 11. During the operation of the system, the ventilation amount V ventilated by the ventilation unit 6 is set based on the output of the ventilation unit 6 (the number of rotations per unit time of the drive unit 62). In this case, it is preferable to consider clogging of the filter 17. Here, even if the output of the ventilation unit 6 is large, when the degree of progress of clogging of the filter 17 is high, the ventilation amount V that is the amount of air flowing into the storage chamber 10 from the intake port 11 decreases. Further, even when the output of the ventilation unit 6 is normal, when the degree of clogging of the filter 17 is low, a ventilation amount V that is the amount of air flowing into the storage chamber 10 from the intake port 11 is secured.

  FIG. 5 shows a flowchart of an example of control executed by the control unit 100. The flowchart is not limited to this. As shown in FIG. 5, the control unit 100 reads system information about each sensor (step S202), and obtains the internal temperature T of the storage chamber 10 based on a signal from the temperature sensor 100t (step S204). Further, the control unit 100 obtains a necessary ventilation amount V according to the internal temperature T of the storage chamber 10 (step S206). Next, the rotation speed N per unit time of the drive unit 2 of the ventilation unit 6 for obtaining the ventilation amount V is obtained (step S208). In this case, it is preferable to consider the degree of filter clogging. In this case, in the area of the storage element 100c built in the control unit 100, the ventilation amount V and the rotational speed N per unit time of the driving unit 2 of the ventilation unit 6, that is, driving, according to the internal temperature T of the storage chamber 10 It is preferable that data indicating characteristics that relatively increase the output of the unit 62 is stored as a map. That is, on the map, when the internal temperature T of the storage chamber 10 is low, the map shows data indicating characteristics of relatively reducing the rotational speed N per unit time of the driving unit 2 of the ventilation unit 6, that is, the output of the driving unit 62. Is stored as Note that an arithmetic expression indicating the above map characteristics is stored instead of the map, and the arithmetic expression may be calculated based on the arithmetic expression each time.

  Regarding the current clogging degree of the filter 17, the clogging degree of the filter 17 can be obtained based on the cumulative operation time and / or the cumulative ventilation amount accumulated from the time when the previous maintenance of the filter 17 is finished. The cumulative ventilation volume can be obtained by estimating the ventilation volume V based on the rotation speed N of the ventilation section and accumulating this from the previous maintenance end time. In general, the cumulative operating time is approximately equal to the cumulative ventilation time.

  Generally, when the accumulated operation time or accumulated ventilation time from the time when the maintenance of the filter 17 was completed last time is long, the degree of clogging of the filter 17 is large. When the cumulative operation time or the cumulative ventilation time is short, the degree of clogging of the filter 17 is small. The accumulated power generation amount may be used as a reference. In this case, generally, when the accumulated power generation amount accumulated from the time when the maintenance was last completed for the filter 17 is large, the degree of clogging of the filter 17 is large. When the accumulated power generation amount is small, the degree of clogging of the filter 17 is small. Such data is stored in the area of the storage element 100c of the control unit 100 as a map or an arithmetic expression. When maintenance of the maintenance parts such as the filter 17 is completed, it is preferable that the cumulative operation time, the cumulative ventilation time, and the cumulative power generation amount are automatically reset when a maintenance person or the like operates a maintenance completion switch in the system.

  Further, the control unit 100 extracts the reference concentration in the gas leakage determination process based on the ventilation amount V of the ventilation unit 6 based on the map or the arithmetic expression stored in the storage element 100c (step S212), and the gas leakage A reference density in the determination process is determined (step S214). In the gas leak determination process of the gas leak, the control unit 100 determines that the gas leak is detected when the gas concentration detected by the gas leak sensor 100m is higher than the reference concentration in the gas leak determination process, and the alarm signal Ar is output to the alarm 110. And the alarm device 110 issues an alarm. In order to prevent hunting, the system waits for a predetermined time (step S216), and then returns to step S202.

(Embodiment 4)
FIG. 6 shows a fourth embodiment. The present embodiment has basically the same configuration and the same function and effect as the above-described embodiments. As shown in FIG. 6, the housing chamber 10 of the housing 1 is divided by a partition wall 18 into a lower first housing chamber 10f and an upper second housing chamber 10s. The first storage chamber 10 f communicates with the intake port 11. The second storage chamber 10 s communicates with the exhaust port 12. The partition wall 18 is provided with a ventilation part 6. The ventilation unit includes a ventilation blade 60 and a drive unit 62 formed by a drive motor that rotationally drives the ventilation blade 60.

  A fuel cell power generation module 9 is accommodated in the second storage chamber 10s. The power generation module 9 includes a stack 7 formed by assembling a plurality of single cells, a reforming device 4 for reforming a reforming fuel material with steam to generate an anode gas containing hydrogen as a main component, and reforming It has the combustion part 2 which forms the space for combustion located between the apparatus 4 and the stack 7, and the heat insulation wall 90 with the high heat insulation which covers the combustion part 2, the stack 7, and the reformer 4 from the outside. The fuel cell constituting the stack 7 is in the form of a solid oxide, and the operating temperature during the power generation operation is as high as 400 ° C., 500 ° C., 600 ° C.

  In FIG. 6, when the air supply device 3 disposed in the first storage chamber 10 f is activated, the air in the first storage chamber 10 f is conveyed from the suction port 31 of the air supply device 3 to the air supply passage 34 and further generates power. The air is supplied as combustion air or cathode gas into the heat insulating wall 90 of the module 9.

  As shown in FIG. 6, the reformer 4 includes an evaporation unit 410 that generates steam from the reforming water, and a reforming unit 420 that includes a reforming catalyst. The reforming fuel is supplied from the reforming fuel passage 40 to the reforming unit 420 via the evaporation unit 410. The reforming fuel supplied to the reforming unit 420 is reformed by the water vapor generated in the evaporation unit 410 and becomes an anode gas (anode fluid) containing hydrogen. The anode gas generated in the reforming unit 420 is supplied to the anode of the stack 7 through the anode gas passage 78 and used for the power generation reaction, and rises to the combustion unit 2 on the upper side of the stack 7, so that the combustion unit 2 Are burned with combustion air as combustion fuel to form a combustion flame 200. As described above, the combustion flame 200 in the combustion unit 2 heats the evaporation unit 410 and the reforming unit 420 of the reformer 4.

  When the system is in operation, the ventilation unit 6 operates and the ventilation blades 60 rotate, and a suction action occurs on the back surface 6r side of the ventilation unit 6. Then, fresh air in the outside 14 is sucked into the storage chamber 10f along the arrow X1 direction from the intake port 11 of the housing 1, and further flows through the opening 19 of the partition wall 18 along the arrow X5 direction to be second stored. After entering the chamber 10 s and further contacting the heat insulating wall 90 of the power generation module 9 in the second storage chamber 10 s to cool the power generation module 9, it is discharged from the exhaust port 12 to the outside 14 in the direction of arrow X2. When the system is operated in this way, the ventilation unit 6 operates to ventilate the first storage chamber 10f and the second storage chamber 10s.

  As shown in FIG. 6, a gas leak sensor 100 m and a temperature sensor 100 t are arranged in the upper part of the storage chamber 10. In particular, a gas leak sensor 100m and a temperature sensor 100t are disposed near the exhaust port 12 in the upper part of the storage chamber 10. In the unlikely event that a gas leak occurs due to loosening of the piping in the storage chamber 10, it is detected by the gas leak sensor 100m. Signals from the sensors 100m and 100t are input to the control unit 100.

  According to the present embodiment, the control unit 100 functioning as the determination unit performs the ventilation process of the storage chamber 10 by operating the ventilation unit 6 during the operation such as the system start-up operation, the power generation operation, and the stop operation. To do. And the control part 100 performs the gas leak determination process of a gas leak, when performing the ventilation process. Accordingly, in the gas leak determination process, when the concentration of the gas detected by the gas leak sensor 100m is larger than the reference concentration in the gas leak determination process, the control unit 100 determines that the gas leak has occurred. Then, the control unit 100 notifies the alarm device 110 of the alarm signal Ar. The alarm device 110 issues an alarm and notifies the user, maintenance personnel, etc. of the gas leak.

  As described above, when the control unit 100 executes the gas leak determination process, the control unit 100 changes the reference concentration according to the ventilation amount V of the storage chamber 10. In particular, the control unit 100 has a characteristic line CA shown in FIGS. 2 and 3 when the ventilation volume V of the storage chamber 10 is relatively large, compared to when the ventilation volume V of the storage chamber 10 is relatively small. , CB, the reference concentration in the gas leakage determination process is lowered.

  The reason is as follows. That is, when the ventilation amount of the storage chamber 10 is relatively large, the flow rate of the ventilation air discharged from the storage chamber 10 to the outside increases and the flow rate of the ventilation air entering the storage chamber 10 increases. . For this reason, even if a gas leak has occurred in the storage chamber 10, the dilution rate at which the leaked gas is diluted with the air for ventilation is high. In this case, the gas leak sensor 100m detects the diluted gas concentration. As a result, the control unit 100 may not be able to detect the gas leak even though the gas leak has occurred in the storage chamber 10.

  Therefore, according to the present embodiment, the control unit 100 is configured such that when the ventilation volume of the storage chamber 10 is relatively large, the control unit 100 does not leak gas compared to when the ventilation volume of the storage chamber 10 is relatively small. The reference concentration in the gas leak judgment process is reduced. For this reason, when gas leakage has occurred in the storage chamber 10, even if the dilution rate at which the leaked gas is diluted increases, the control unit 100 ensures good gas leakage in the storage chamber 10 in the gas leakage determination process. Can be detected. Since the stack 7 is a solid oxide fuel cell, the power generation operation temperature is as high as 400 ° C. or higher and 500 ° C. or higher, for example. For this reason, the ventilation amount V is large in order to suppress the heat accumulation in the storage chamber 10.

  Also in this embodiment, it is preferable that the control part 100 performs control which suppresses the big fluctuation | variation of the internal temperature of the storage chamber 10. FIG. That is, when the system is operated in summer, a tropical zone, or when the system is operated for a long time in an excessively high output state, the temperature of the storage chamber 10 detected by the temperature sensor 100t is excessively high. There is a fear. In this case, the control unit 100 relatively increases the number of rotations per unit time of the drive unit 62 of the ventilation unit 6 (output of the ventilation unit 6), and the amount of air entering the storage chamber 10 from the intake port 11 And the amount of air discharged from the exhaust port 12 to the outside 14 is increased. Thereby, the ventilation amount V of the storage chamber 10 is relatively increased, and an excessive increase in the temperature of the storage chamber 10 is suppressed. In addition, when the system is operated in winter or in a cold region, the temperature of the storage chamber 10 detected by the temperature sensor 100t may be excessively low. In such a case, the control unit 100 relatively reduces the number of rotations per unit time of the drive unit 62 of the ventilation unit 6 (output of the drive unit 62), and enters the storage chamber 10 from the intake port 11. The amount of air discharged from the exhaust port 12 to the outside 14 is relatively decreased while the amount is relatively decreased. Thereby, the ventilation amount V of the storage chamber 10 is relatively decreased, and an excessive decrease in the temperature of the storage chamber 10 is suppressed. Thereby, the excessive increase in temperature and the excessive decrease in the internal temperature of the storage chamber 10 are suppressed, and a large variation in the internal temperature of the storage chamber 10 is suppressed. Thus, according to this embodiment, in order to suppress the big fluctuation | variation of the internal temperature of the storage chamber 10, the ventilation volume V is fluctuate | varied by the ventilation part 6. FIG.

  As described above, if the ventilation amount V is varied by the ventilation unit 6, a large variation in the interior of the storage chamber 10 is well suppressed, and the protection of the system can be improved.

  Furthermore, the control unit 100 is configured so that the control unit 100 in FIG. 2 and FIG. 3 when the ventilation amount V of the storage chamber 10 is relatively large compared to when the ventilation amount V of the storage chamber 10 is relatively small. Based on the characteristic lines CA and CB shown, the reference concentration in the gas leakage determination process is lowered. For this reason, in the unlikely event that a gas leak has occurred in the storage chamber 10, even if the dilution rate at which the leaked gas is diluted increases, the control unit 100 performs the gas leak in the storage chamber 10 in the gas leak determination process. Can be detected well.

(Embodiment 5)
Since this embodiment has basically the same configuration and the same function and effect as the above-described embodiments, FIGS. 1 to 3 and FIG. 6 can be applied mutatis mutandis. When the power generation of the stack 7 is continuously performed for a predetermined time or more in a high output state, the internal temperature T of the storage chamber 10 is relatively increased, and heat is easily generated. Furthermore, the flow rates of the anode gas and cathode gas supplied to the stack 7 are increased. For this reason, in order to cope with an emergency gas (reforming fuel and / or anode gas) leakage, the control unit 10 increases the output of the drive unit 62 of the ventilation unit 6 to relatively increase the ventilation amount V. Let In this case, compared with the case where the ventilation amount V of the storage chamber 10 is relatively small, the control unit 100 determines the reference in the gas leakage determination process based on the characteristic lines CA and CB shown in FIGS. The concentration is decreased according to the ventilation volume V. For this reason, in the unlikely event that a gas leak has occurred in the storage chamber 10, even if the dilution rate at which the leaked gas is diluted increases, the control unit 100 performs the gas leak in the storage chamber 10 in the gas leak determination process. Can be detected well.

  On the other hand, when the power generation of the stack 7 is operated in a low output state, the internal temperature T of the storage chamber 10 relatively decreases. For this reason, the output of the drive part 62 of the ventilation part 6 is decreased, and the ventilation volume V is decreased relatively. In this case, as compared with the case where the ventilation volume V of the storage chamber 10 is relatively large, the control unit 100 performs the gas leak determination process based on the characteristic lines CA and CB shown in FIGS. The reference concentration in is appropriately increased according to the ventilation volume V. For this reason, it is possible to suppress erroneous detection of gas leak in the determination process even though no gas leak has actually occurred.

  (Others) The present invention is not limited to the embodiment described above and shown in the drawings, and can be implemented with appropriate modifications within a range not departing from the gist. The following technical idea can be understood from the above description.

  [Additional Item 1] A fuel cell having an anode to which an anode fluid is supplied and a cathode to which a cathode fluid is supplied, a casing having a storage chamber for storing the fuel cell, and the inside of the storage chamber of the casing are ventilated. A ventilation unit; a gas sensor that detects gas leakage in the housing chamber of the housing; and a determination unit that executes gas leakage determination processing for determining gas leakage when the concentration of gas detected by the gas sensor is greater than a reference concentration. Fuel cell system. The determination unit can change the ventilation volume V of the storage chamber and the reference concentration in the gas leak determination process according to the internal temperature of the storage chamber.

  [Additional Item 2] A fuel cell having an anode to which an anode fluid is supplied and a cathode to which a cathode fluid is supplied, a casing having a storage chamber for storing the fuel cell, and the inside of the storage chamber of the casing are ventilated. A ventilation unit; a gas sensor that detects gas leakage in the housing chamber of the housing; and a determination unit that executes a gas leakage determination process for determining gas leakage when the concentration of gas detected by the gas sensor is higher than a reference concentration. A fuel cell system comprising: a determination unit that calculates a ventilation amount V of the storage chamber according to an internal temperature of the storage chamber, and changes a reference concentration in the gas leakage determination process according to the ventilation amount V.

  The present invention can be used for, for example, a fuel cell system for stationary use, vehicle use, electric equipment use, electronic equipment use, portable use, portable use, plant use, and the like.

  1 is a housing, 10 is a storage chamber, 11 is an intake port (ventilation port), 12 is an exhaust port (ventilation port), 17 is a filter, 18 is a partition wall, 2 is a combustion unit, 3 is an air supply device, 4 is A reformer, 6 is a ventilation unit, 60 is a ventilation blade, 62 is a drive unit, 8 is an electrical system component, 100 is a control unit, 100c is a storage element, 100m is a gas leak sensor (gas sensor), and 100t is a temperature sensor. .

Claims (2)

A fuel cell having an anode to which an anode fluid is supplied and a cathode to which a cathode fluid is supplied; a housing having a storage chamber for storing the fuel cell; and a ventilation unit for ventilating the interior of the storage chamber of the housing when a gas sensor for sensing the gas leakage of the fuel source gas or the anode fluid in the storage chamber of the housing, when the concentration of gas in which the gas sensor has detected is higher than the reference density, gas leakage and determining gas leakage determination A determination unit that executes processing, and a temperature sensor that detects the temperature of the storage chamber,
When the temperature of the storage chamber detected by the temperature sensor is relatively high, the ventilation unit is configured to ventilate the storage chamber as compared to when the temperature of the storage chamber detected by the temperature sensor is relatively low. Increasing the amount V, suppressing temperature fluctuations in the storage chamber,
The determination unit reduces the reference concentration in the gas leakage determination process when the ventilation volume V of the storage chamber is relatively large, compared to when the ventilation volume V of the storage chamber is relatively small, A fuel cell system in which a reference concentration in the gas leakage determination process is changed continuously or stepwise by three or more values according to a ventilation amount V of a storage chamber.   In Claim 1, the said housing | casing has the inlet port connected to the said storage chamber, and the filter for purification | cleaning provided in the said inlet port, The said ventilation amount V in the said gas leak determination process is the said ventilation | gas_flowing amount V A fuel cell system that is set based on the output of the ventilation section and the clogging of the filter.

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