JP2012074303A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system in which gas leakage inspection of an assist combustion route is performed.SOLUTION: A fuel cell system 100 includes: a reformer 1 generating hydrogen-containing gas due to reforming reaction using material gas; a combustor 2 heating the reformer 1; a first gas flow path 4 through which the material gas flowing into the reformer 1 passes; a second gas flow path 12 through which the material gas flows into the combustor 2 to bypass the reformer 1; a fuel cell 3 generating power using the hydrogen-containing gas; and a gas leakage inspection device 17 supplying the material gas to the second gas flow path 12 to inspect gas leakage of the second gas flow path 12 before supplying the material gas to the first gas flow path 4 to inspect gas leakage of the first gas flow path 4.

Description

  The present invention relates to a fuel cell system. In particular, the present invention relates to a gas leak test for a fuel cell system.

  A fuel cell system is a device that generates electricity by an electrochemical reaction between hydrogen in fuel gas and oxygen in air. The fuel gas can be generated from a raw material gas by a reforming reaction in, for example, a reformer. The reformer is provided with a combustor (for example, a combustion burner) that heats the reformer to a temperature suitable for the steam reforming reaction.

  In such a fuel cell system, since a combustible gas flows, it has been proposed to perform a gas leak diagnosis. Specifically, the fuel cell system is configured to supply a raw material gas to a fluid flow path passing through a reformer and perform a raw material gas leakage diagnosis. (For example, see Patent Document 1)

JP 2008-108446 A

  By the way, in the fuel cell system described in Patent Document 1, the raw material gas flow path through which the raw material gas flows is branched, and the raw material gas bypasses the reformer and is supplied to the combustor as fuel for combustion. (Hereinafter sometimes referred to as “assist combustion path”). However, in the gas leak diagnosis of the above conventional fuel cell system, gas leakage in the assist combustion path is not taken into consideration, and thus there is no gas leakage in the fluid flow path passing through the reformer. You may mistakenly diagnose that there is a gas leak.

  The present invention has been made in view of such circumstances, and in a fuel cell system having an assist combustion path, provides a fuel cell system in which errors in a gas leak test are reduced as compared with a conventional fuel cell system. For the purpose.

  In order to solve the above problems, a first fuel cell system includes a reformer that generates a hydrogen-containing gas by a reforming reaction using a raw material gas, a combustor that heats the reformer, and the reformer. The first gas flow path through which the raw material gas flowing into the gas flows, the second gas flow path through which the raw material gas flowing into the combustor bypassing the reformer, and the hydrogen-containing gas are used to generate power. Before the fuel cell and the source gas are supplied to the first gas flow path to check for gas leakage in the first gas flow path, the raw material is supplied to the second gas flow path and the second gas flow path A gas leak tester for inspecting gas leaks in the gas flow path.

  Further, the second fuel cell system includes a first on-off valve provided in a first gas flow path upstream of the reformer, and a first gas flow downstream of the first on-off valve. A second on-off valve provided in the passage, and a sealing mechanism provided in the second gas flow path, wherein the gas leak tester includes the first on-off valve and the second on-off valve. In a state where the valve is closed and the second gas flow path is sealed by the sealing mechanism, the source gas is supplied to the second gas flow path, thereby preventing the gas leakage of the second gas flow path. inspect.

  In the third fuel cell system, the gas leak tester closes the second on-off valve and seals the second gas flow path with the sealing mechanism. After supplying the source gas to the flow path and the second gas flow path, the first on-off valve is closed to check for gas leakage in the second gas flow path.

  Further, in the fourth fuel cell system, the gas leak tester precedes the test when performing the gas leak test of the first gas flow channel after the gas leak test of the second gas flow channel. And a sticking tester for performing a sticking test on the first on-off valve and the second on-off valve.

  In the fifth fuel cell system, the sticking tester performs the sticking test after opening the first gas flow path to the atmosphere.

  In addition, the sixth fuel cell system includes a pressure detector that detects a supply pressure of the raw material gas, and the sticking inspector (i) after closing the first on-off valve and the second on-off valve. While supplying the source gas, the first on-off valve and the second on-off valve are opened in this order, and (ii) the pressure difference detected by the pressure detector before and after the second on-off valve is opened. Based on this, the sticking is inspected.

  In addition, the seventh fuel cell system, when the gas leak detector detects a gas leak in the second gas flow path, performs a supplementary operation that is performed after the hydrogen-containing gas generating operation of the reformer is stopped. A supplementary pressure operation prohibiting device for prohibiting the pressure operation is provided.

  Further, the eighth fuel cell system prohibits a supplementary pressure operation that inhibits a supplementary pressure operation that is performed after the operation of generating the hydrogen-containing gas of the reformer is stopped when the sticking is detected by the sticking tester. Equipped with a bowl.

  According to the present invention, in a fuel cell system having an assist combustion path, a fuel cell system can be obtained in which errors in a gas leak inspection are reduced as compared with a conventional fuel cell system.

FIG. 2 is a block diagram showing a configuration example of the fuel cell system according to the first embodiment. 3 is a flowchart showing a flow of gas leak inspection in the fuel cell system of the first embodiment. 3 is a flowchart showing a specific example of a flow of gas leak inspection in the fuel cell system of Embodiment 1. 6 is a flowchart showing another specific example of a flow of gas leakage inspection in the fuel cell system of the first embodiment. 7 is a flowchart showing a flow of gas leak inspection in the fuel cell system of the second embodiment. 6 is a flowchart showing a specific example of an on-off valve adhesion test in the fuel cell system according to the second embodiment. 7 is a flowchart showing a flow of gas leak inspection in the fuel cell system of Embodiment 3.

(Embodiment 1)
In the fuel cell system of Embodiment 1, a reformer that generates a hydrogen-containing gas by a reforming reaction using a raw material gas, a combustor that heats the reformer, and a raw material gas that flows into the reformer flows. A first gas passage, a second gas passage through which a raw material gas that bypasses the reformer and flows into the combustor flows, a fuel cell that generates power using a hydrogen-containing gas, and the raw material gas from the first gas passage A gas leak tester that supplies a raw material to the second gas flow path and inspects the gas leak of the second gas flow path before supplying the gas flow path and inspecting the gas leak of the first gas flow path. And comprising.

  With this configuration, since the gas leak in the second gas flow path that functions as the assist combustion path is inspected, in the fuel cell system including the first gas flow path, the gas leak inspection can be performed more than the conventional fuel cell system. Errors are reduced.

  The gas leak tester includes, for example, an arithmetic processing unit that executes a control program related to a gas leak test and a storage unit that stores the control program.

  Hereinafter, specific configuration examples and operation examples of the fuel cell system according to Embodiment 1 will be described with reference to the drawings.

  However, the following specific description only exemplifies the characteristic form of each fuel cell system. For example, when the following specific examples are described with appropriate reference numerals attached to the same or corresponding terms as the terms specifying the respective fuel cell systems, the specific device includes the corresponding fuels described above. It is an example of the component of a battery system.

  Therefore, the characteristic form of each fuel cell system is not limited by the following specific description.

[Configuration example of fuel cell system]
FIG. 1 is a block diagram showing a configuration example of the fuel cell system according to the present embodiment.

  As shown in FIG. 1, the fuel cell system 100 generates a fuel cell 3 that generates power using a hydrogen-containing gas and an oxidant gas (for example, air), and a hydrogen-containing gas supplied to the anode of the fuel cell 3. A reformer 1 (details will be described later) and an oxidant gas supplier 16 for supplying an oxidant gas to the cathode of the fuel cell 3 are provided. In the fuel cell 3, the hydrogen-containing gas supplied to the anode of the fuel cell 3 and the oxidant gas supplied to the cathode of the fuel cell 3 react electrochemically (exothermic reaction), and electric power and heat are generated. appear. The electric power generated by the fuel cell 3 can be used in various electric devices, for example. Further, the heat generated by the fuel cell 3 can be used for various purposes. For example, it can be used in home heating and hot water supply. The internal structure of the fuel cell is known. Therefore, the detailed description is abbreviate | omitted.

  As shown in FIG. 1, the fuel cell system 100 includes a reformer 1 that generates a hydrogen-containing gas by a reforming reaction using a raw material gas and water vapor. However, the fuel cell system 100 includes a reformer (not shown) that reduces carbon monoxide by a shift reaction in order to reduce carbon monoxide in the hydrogen-containing gas in addition to the reformer 1 depending on the device structure. In addition, at least one of carbon monoxide removers (not shown) for reducing carbon monoxide by an oxidation reaction may be provided.

  When the raw material gas and water vapor are supplied to the reformer 1, the reformer 1 causes a reforming reaction in a reforming catalyst body (not shown). Then, in the reformer 1, a hydrogen-containing gas is generated. The internal structure of the reformer 1 is known. Therefore, the detailed description is abbreviate | omitted.

  Further, as shown in FIG. 1, the fuel cell system 100 includes a water supply unit 14 used for supplying reforming reaction water to the reformer 1 and a raw material gas supply path before branching to the combustion fuel flow path 20. The raw material gas main valve 6 provided in 18 and the pressure detector 7 provided in the raw material gas supply path 18 downstream from the raw material gas main valve 6 are provided.

  The source gas supply path 18 is connected to a source gas supply source (city gas infrastructure, propane gas cylinder, etc.). For example, an on-off valve is used as the source gas source valve 6.

  The water supply path 19 is connected to a water supply source (water infrastructure, water tank, etc.). As the water supply device 14, for example, at least one of a pump and a flow rate adjustment valve is used.

  At a high temperature of about 600 ° C. to 700 ° C., the reforming reaction (endothermic reaction) of the reforming catalyst body is accelerated. For this reason, in order for the reforming reaction to proceed in the reformer 1, a combustor 2 (for example, a combustion burner) that can apply heat to the reformer 1 from the outside is required.

  Therefore, as shown in FIG. 1, the fuel cell system 100 supplies a combustor 2 for heating the reformer 1 and combustion air (hereinafter sometimes abbreviated as “combustion air”) to the combustor 2. And an air supplier 15.

  As the air supply device 15, for example, a fan that pumps air (air) containing oxygen necessary for combustion to the combustor 2 can be used. However, the air supply unit 15 is not limited to a fan, and may be another device as long as it can supply air, for example, a blower.

  The details of the supply of combustion fuel gas (hereinafter sometimes abbreviated as “combustion fuel”) to the combustor 2 will be described later.

  When an appropriate amount of combustion fuel and an appropriate amount of combustion air are supplied to the combustor 2, combustion of the mixture gas of the combustion fuel and the combustion air occurs in the combustor 2. Then, high-temperature combustion exhaust gas is generated in the combustor 2. The combustion exhaust gas flows through the combustion exhaust gas flow path, and is given heat to the reforming catalyst body of the reformer 1 by heat exchange, and then discharged to the outside (atmosphere). Thus, the inside of the combustor 2 communicates with the atmosphere via an appropriate combustion exhaust gas passage.

  As shown in FIG. 1, the fuel cell system 100 includes a first gas flow path 4 through which the raw material gas flowing into the reformer 1 flows, and a raw material downstream from the branch point to the combustion fuel flow path 20. A first on-off valve 8 provided in the gas supply path 18 for communicating / blocking (communication and blocking) the raw material gas supply path 18 and a first gas flow path 4 downstream of the reformer 1 are provided. And a second on-off valve 9 (for example, an electromagnetic valve) that communicates / blocks the first gas flow path 4. Therefore, formation of a closed space including at least a part of the first gas flow path 4 can be performed using the first on-off valve 8 and the second on-off valve 9.

  As shown in FIG. 1, the first gas flow path 4 on the downstream side of the reformer 1 is branched in the middle. Specifically, the first gas flow path 4 is sent from the reformer 1 to the first gas flow path 4. The hydrogen-containing gas sent from the reformer 1 is combusted via the bypass gas passage 4A introduced into the combustor 2 so that the hydrogen-containing gas bypasses the fuel cell 3 and the anode of the fuel cell 3. And an anode gas flow path 4B introduced into the vessel 2.

  The second on-off valve 9 includes a bypass on-off valve 9A for communicating / blocking the bypass gas passage 4A and an anode upstream side opening / closing valve 9B for communicating / blocking the anode gas passage 4B on the upstream side of the fuel cell 3. And an anode downstream side on-off valve 9C for communicating / blocking the anode gas passage 4B on the downstream side of the fuel cell 3.

  Therefore, when the bypass opening / closing valve 9A is opened and at least one of the anode upstream side opening / closing valve 9B and the anode downstream side opening / closing valve 9C is closed, the combustible gas (for example, hydrogen-containing gas) sent from the reformer 1 is closed. Can be used as combustion fuel for the combustor 2.

  On the other hand, when the bypass on-off valve 9A is closed and both the anode upstream side on-off valve 9B and the anode downstream side on-off valve 9C are opened, the combustible gas (for example, hydrogen-containing gas) sent from the anode of the fuel cell 3 is combusted. It can be used as a combustion fuel for the vessel 2.

  Further, as shown in FIG. 1, the fuel cell system 100 includes a second gas passage 12 that bypasses the reformer 1 and flows a raw material gas that flows into the combustor 2, and a second gas passage 12. A third on-off valve 13 provided. The second gas flow path 12 includes a raw material gas supply path 18 upstream of the branch point to the combustion fuel flow path 20 and the combustion fuel flow path 20.

  Therefore, when the third on-off valve 13 is opened, the second gas flow path 12 functions as an assist combustion path, and combustible gas (second source gas) supplied from the source gas supply source is supplied to the combustor 2. It can be used as a combustion fuel.

  In addition, although the 3rd on-off valve 13 was illustrated here as a sealing mechanism which connects and blocks | interconnects the 2nd gas flow path 12, it is not restricted to this. For example, as such a sealing mechanism, a pump having a sealing function may be used instead of the third on-off valve 13.

  In addition, each of the three modes of supplying the combustion fuel to the combustor 2 described above is selected in a timely manner according to the operation state of the fuel cell system 100, and the operation method of the fuel cell system 100 is known. Therefore, the detailed description is abbreviate | omitted.

  As shown in FIG. 1, the fuel cell system 100 includes a controller 17 including an arithmetic processing unit that executes a control program for the fuel cell system and a storage unit that stores the control program. The controller 17 may be composed of a single controller or a plurality of controllers. In addition, the said arithmetic processing part is comprised by CPU, MPU, etc. The storage unit includes a memory or the like.

  The controller 17 controls operations of various control targets of the fuel cell system 100 based on signals from various detectors of the fuel cell system 100.

  Next, an inspection example of gas leakage by the fuel cell system 100 of the present embodiment will be described.

  FIG. 2 is a flowchart showing an example of a gas leak inspection by the fuel cell system of the present embodiment.

  A control program for executing each operation flow shown in FIG. 2 is stored in a storage unit (not shown) of the controller 17. Here, the controller 17 functions as a gas leak tester. Then, the above program is read out by an arithmetic processing unit (not shown) of the controller 17 at an appropriate time (for example, when the fuel cell system 100 is stopped). Based on this program, the controller 17 operates as follows. Is executed while controlling each part of the fuel cell system 100.

  First, a gas leak inspection is performed in the second gas flow path 12 (step S101), and it is determined whether or not a gas leak has occurred in the second gas flow path 12 (step S102).

  When it is determined that there is an abnormality (gas leak) in the gas leak inspection of the second gas flow path 12 (“No” in step S102), appropriate notification means (for example, a notification lamp, a display for notification display) An abnormality (gas leakage) is notified using a panel, a speaker for notification and the like (step S105), and the inspection is completed.

  On the other hand, when it is determined that there is no abnormality (gas leak) in the gas leak inspection of the second gas flow path 12 (“Yes” in step S102), the process proceeds to the next inspection and determination step, and the first gas The flow path 4 is inspected for gas leakage (step S103), and it is determined whether or not gas leakage has occurred in the first gas flow path 4 (step S104).

  When it is determined in the gas leak inspection of the first gas flow path 4 that there is an abnormality (gas leakage) (“No” in step S104), the abnormality (gas leakage) is notified using the notification means. (Step S105), the inspection ends.

  On the other hand, if it is determined that there is no abnormality (gas leakage) in the gas leakage inspection of the first gas flow path 4 (“Yes” in step S104), the inspection ends without any abnormality being notified. To do.

  As described above, the fuel cell system 100 according to the present embodiment functions as an assist combustion path before the gas leak inspection of the first gas passage 4 as in the operation flow of the gas leak inspection shown in FIG. Gas leaks in the second gas flow path 2 are inspected.

[Example]
Next, examples of the fuel cell system 100 according to Embodiment 1 will be described.

  Further, the fuel cell system of the present embodiment is provided in a first on-off valve provided in the raw material gas supply path upstream of the reformer and in a first gas flow path downstream of the first on-off valve. A gas leakage inspection device that closes the first on-off valve and the second on-off valve and seals the second on-off valve, and a sealing mechanism provided in the second gas flow path. Even if the gas leakage in the second gas channel is inspected by supplying the source gas to the second gas channel with the mechanism sealing the second gas channel upstream of the sealing mechanism. Good.

  With this configuration, the second gas flow path leak test is performed in comparison with the mode in which the gas leak test of the second gas flow path is performed with the first open / close valve closed and the second open / close valve opened. Reliability is improved.

Here, the sealing mechanism may be in any form as long as it can communicate and block the gas flow path. For example, an on-off valve, a pump provided with a sealing function provided in the gas flow path, and the like are exemplified.
The details will be described below.

  FIG. 3 is a flowchart showing a specific example of gas leakage inspection in the fuel cell system of the present embodiment.

  A control program for executing each operation flow shown in FIG. 3 is stored in the storage unit of the controller 17.

  Then, the program is read out by an arithmetic processing unit (not shown) at an appropriate time (for example, when the fuel cell system 100 is stopped), and the controller 7 performs the following operation based on this program. This is executed while controlling each part of 100.

  First, the first on-off valve 8, the second on-off valve 9, and the third on-off valve 13 are all closed (step S201).

  Next, the source gas source valve 6 is opened, and source gas is supplied from the source gas source valve 6 to the gas channel including the second gas channel between the third on-off valve 13 (step S202). When the gas flow path reaches a predetermined pressure due to the supply of the source gas, the source gas source valve 6 is closed (step S203). The operation of supplying the source gas until the predetermined gas flow path reaches a predetermined pressure as in steps S202 to S203 is hereinafter referred to as “compression”. The predetermined pressure is set as, for example, the supply pressure of the source gas supply source, but is not limited to this pressure, and is set as appropriate. In addition, you may detect directly with the pressure detector 7 that it became the said predetermined pressure, and you may detect indirectly based on the elapsed time after starting step S202, the form Is optional.

  In this state, after a predetermined time has elapsed, the pressure detector 7 is used to detect the pressure value P1 of the gas flow path including the second gas flow path between the source gas main valve 6 and the third on-off valve 13. Then, it is determined whether or not the pressure value P1 of the pressure detector 7 at this time is equal to or greater than the set value A (step S204). The set value A is a reference pressure for determining whether or not a gas leak has occurred. For example, when the predetermined pressure is the supply pressure of the source gas supply source, the set value A is greater than the supply pressure of the source gas supply source. Is set to a smaller value. For example, when city gas is used as the raw material gas, the standard value of the gas supply pressure of the city gas is in the range of about 1 kPa to 2.5 kPa, and therefore a value slightly smaller than the minimum value (1 kPa) of the standard value (for example, , 0.80 kPa) may be set. The predetermined time is set to a time necessary for the detected pressure of the pressure detector 7 to be equal to or lower than the set value A when a gas leak occurs in the second gas flow path 12.

  When the pressure value P1 after a lapse of a predetermined time from step S203 is smaller than the set value A (in the case of “No” in step S204), it is determined that gas leakage has occurred in the second gas flow path 12 (step S205).

  Note that the gas leakage inspection of the second gas flow path 12 is performed in a state where all of the first on-off valve 8, the second on-off valve 9, and the third on-off valve 13 are closed. You may perform in the state which opened the 2 on-off valve 9. FIG. However, since the possibility of erroneously detecting a gas leak passing through the first on-off valve 8 as a gas leak of the second gas flow path 12 is reduced, the second on-off valve 9 is also closed as in the above flow. Is preferably performed.

  If it is determined that an abnormality has occurred in which gas passes through the first on-off valve 8 even when the first on-off valve 8 is closed, it is determined in step S205 that a gas leak has occurred in the second gas flow path 12. there is a possibility. However, since the amount of gas leakage that passes through the first on-off valve 8 is limited by closing the second on-off valve 9 as described above, the second gas leakage that passes through the first on-off valve 8 is prevented. The possibility of erroneous detection as a gas leak in the gas flow path 12 is reduced.

  Thereafter, all the valves of the fuel cell system 100 are closed (step S206), an abnormality (gas leakage) is notified using the notification means (step S207), and the inspection is completed.

  On the other hand, if the pressure value P1 is greater than or equal to the set value A (“Yes” in step S204), it is determined that no gas leakage has occurred in the second gas flow path. Therefore, in this case, the process proceeds to the next determination step (after step S208).

  First, the first on-off valve 8 is opened (step S208).

  Next, the source gas source valve 6 is opened, the source gas is supplied to the gas flow path including the first gas flow path 4 upstream of the second on-off valve 9, and the tension is executed (step S209). . When the gas flow path reaches a predetermined pressure due to the supply of the raw material gas, the raw material gas main valve 6 is closed to complete the tensioning (step S210). The method for detecting that the predetermined pressure and the gas flow path have reached a predetermined pressure is the same as that described in step S203.

  In this state, after a lapse of a predetermined time, the pressure detector 7 is used to detect the pressure value P1 of the source gas sent from the source gas source valve 6, and the pressure value P1 of the pressure detector 7 at this time is set. It is determined again whether or not the value is A or more (step S211). The predetermined time is set to a time required for the detected pressure of the pressure detector 7 to be equal to or lower than the set value A when a gas leak occurs in the first gas flow path 4.

  When the pressure value P1 after a lapse of a predetermined time from step S210 is smaller than the set value A (in the case of “No” in step S211), it is determined that gas leakage has occurred in the first gas flow path 4 (step S21). S212).

  Thereafter, all the valves of the fuel cell system 100 are closed (step S213), an abnormality (gas leakage) is notified using the notification means (step S214), and the inspection is completed.

  On the other hand, if the pressure value P1 is greater than or equal to the set value A (“Yes” in step S211), it is determined that no gas leak has occurred in the second gas flow path, and no abnormality is reported, and the fuel cell All the valves of the system 100 are closed (step S215), and the inspection is finished.

[Modification]
Next, a modification of the fuel cell system 100 of Embodiment 1 will be described.

  In the fuel cell system of this modification, the gas leak tester closes the second on-off valve and seals the second gas channel with the sealing mechanism, and the first gas channel and the second gas channel After supplying the source gas to the gas flow path, the first on-off valve may be closed to check for gas leakage in the second gas flow path.

With this configuration, the reliability of gas leakage in the second gas passage is improved as compared with the fuel cell system of the above embodiment.
FIG. 4 is a flowchart showing another specific example of the gas leak test in the fuel cell system according to this modification. However, the operation after step S306 in FIG. 4 is the same as the operation after step S204 in FIG. Therefore, description of each step after step S306 in FIG. 4 is omitted.

A control program for executing each operation flow shown in FIG. 4 is stored in a storage unit (not shown) of the controller 17.
The controller 17 functions as a gas leak tester. Then, the program is read out to the arithmetic processing unit at an appropriate time (for example, when the fuel cell system 100 is stopped), and based on this program, the controller 17 controls each part of the fuel cell system 100 as follows. Run while.

  First, the first on-off valve 8, the second on-off valve 9, and the third on-off valve 13 are all closed (step S301).

  Next, the source gas main valve 6 is opened (step S302).

  Next, the first on-off valve 8 is opened (step S303), the raw material gas is supplied to the gas passage including the first gas passage 4 upstream from the second on-off valve 9, and the tension is executed. The When the gas flow path reaches a predetermined pressure due to the supply of the source gas, the first on-off valve 8 is closed (step S304), the source gas source valve 6 is closed, and the tensioning is completed (step S304). S305). The method for detecting that the predetermined pressure and the gas flow path have reached a predetermined pressure is the same as that described in step S203.

  In this state, the same processing as the operation after step S204 in FIG. 3 is performed.

  As described above, in the fuel cell system 100 of the present modification, unlike the fuel cell system of the above-described embodiment, the raw material gas supply process to the gas flow path before the gas leakage determination of the second gas flow path (before step S306). Thus, the source gas is also supplied to the gas flow path between the first on-off valve 8 and the second on-off valve until a predetermined pressure is reached. Therefore, even if the first on-off valve 8 is closed and an abnormality occurs in which the gas passes through, the distance between the first on-off valve 8 and the second on-off valve 9 is smaller than that in the above embodiment. The internal pressure of the gas flow path is high, and there is a high possibility that the amount of gas passing through the first on-off valve 8 is more limited. In this way, the possibility of erroneously detecting a gas leak passing through the first on-off valve 8 as a gas leak in the second gas flow path 12 is reduced as compared with the above embodiment.

(Embodiment 2)
In the fuel cell system according to Embodiment 2, when the gas leak tester performs the gas leak test of the first gas flow path after the gas leak test of the second gas flow path, the first test is performed prior to this test. You may provide the sticking tester which performs the sticking test | inspection of 1 on-off valve and 2nd on-off valve.

  If sticking occurs in at least one of the first on-off valve and the second on-off valve, the gas leak inspection of the first gas flow path may not be executed normally. For example, if the first on-off valve is closed and stuck, the pressure on the first gas flow path before the gas leak inspection is not executed, and the presence or absence of the gas leak cannot be detected. However, with such a configuration, the adhesion inspection of the first on-off valve and the second on-off valve is performed before the gas leak inspection, so that the reliability of the gas leak inspection is further improved.

  Here, the adhering of the on-off valve means a state in which the on-off valve does not normally open / close due to close contact between components of the on-off valve.

  The sticking inspector includes an arithmetic processing unit that executes a control program related to sticking inspection, and a storage unit that stores the control program.

  Hereinafter, specific configuration examples and operation examples of the fuel cell system according to Embodiment 2 will be described with reference to the drawings.

  Next, an inspection example of gas leakage by the fuel cell system 100 of the present embodiment will be described.

  FIG. 5 is a flowchart showing an example of a gas leak test by the fuel cell system of the present embodiment.

  A control program for executing each operation flow shown in FIG. 5 is stored in a storage unit (not shown) of the controller 17. Here, the controller 17 functions as a gas leak tester and a sticking tester. Then, the above program is read out by an arithmetic processing unit (not shown) of the controller 17 at an appropriate time (for example, when the fuel cell system 100 is stopped). Based on this program, the controller 17 operates as follows. Is executed while controlling each part of the fuel cell system 100.

  First, a gas leak inspection is performed in the second gas flow path 12 (step S401), and it is determined whether or not a gas leak has occurred in the second gas flow path 12 (step S402).

  When it is determined that there is an abnormality (gas leakage) in the gas leakage inspection of the second gas flow path 12 (in the case of “No” in step S402), the abnormality (gas leakage) is notified using the notification means. (Step S407), the inspection ends.

  On the other hand, when it is determined that there is no abnormality (gas leakage) in the gas leak inspection of the second gas flow path 12 (“Yes” in step S402), the process proceeds to the next inspection and determination step, and the first opening / closing step is performed. The sticking inspection of the valve 8 and the second on-off valve 9 is performed (step S403), and it is determined whether or not the first on-off valve 8 and the second on-off valve 9 are stuck (step S404).

  If it is determined that at least one of the first on-off valve 8 and the second on-off valve 9 has an abnormality (on-off valve adhering) (in the case of “No” in step S404), the abnormality is detected using the notification means. (Open / close valve sticking) is notified (step S407), and the inspection ends.

  On the other hand, when it is determined that there is no abnormality (open / close valve sticking) in the sticking inspection of the first on-off valve 8 and the second on-off valve 9 (“Yes” in step S404), the next inspection and judgment step is performed. Then, a gas leak inspection is performed on the first gas flow path 4 (step S405), and it is determined whether or not a gas leak has occurred in the first gas flow path 4 (step S406).

  When it is determined that there is an abnormality (gas leakage) in the gas leakage inspection of the first gas flow path 4 (in the case of “No” in step S406), the abnormality (gas leakage) is notified using the notification means. (Step S407), the inspection ends.

  On the other hand, when it is determined that there is no abnormality (gas leakage) in the gas leakage inspection of the first gas flow path 4 (in the case of “Yes” in step S406), the abnormality is not notified and the inspection ends.

  As described above, in the fuel cell system 100 of the present embodiment, the first on-off valve precedes the gas leak inspection of the first gas flow path 4 as shown in the operation flow of the gas leak inspection shown in FIG. 8 and the second on-off valve 9 are inspected for adhesion.

[Example]
Next, examples of the fuel cell system 100 of the present embodiment will be described.

Further, the fuel cell system of the present embodiment may be provided with a pressure detector that detects the supply pressure of the raw material gas, and the sticking inspection device is (i) after closing the first on-off valve and the second on-off valve. While supplying the raw material gas, open the first on-off valve and the second on-off valve in this order, and (ii) check the adhesion based on the pressure difference detected by the pressure detector before and after the opening of the second on-off valve. May be.
An example of a specific operation flow of the first gas flow path 4 and the second gas leak inspection has been described with reference to FIGS. 3 and 4 and will be omitted, and the operation flow of the on-off valve adhesion inspection will be described. .

  FIG. 6 is a flowchart showing a specific example of the on / off valve sticking inspection in the fuel cell system of the present embodiment. In FIG. 6, only the contents of the operation flow of the sticking inspection of the first on-off valve 8 and the second on-off valve 9 are shown.

  A program for executing each operation flow shown in FIG. 6 is stored in a storage unit (not shown) of the controller 17.

  Here, the controller 17 functions as a sticking tester. Then, the above program is read out by the arithmetic processing unit at an appropriate time (for example, when the fuel cell system 100 is stopped), and based on this program, the controller 17 controls each part of the fuel cell system 100 as follows. Run while.

  First, the first on-off valve 8, the second on-off valve 9, and the third on-off valve 13 are all closed (step S501).

  Next, the source gas main valve 6 is opened (step S502).

  Next, the first on-off valve 8 is opened, the raw material gas is supplied to the gas passage including the first gas passage 4 upstream of the second on-off valve 9, and the tensioning is executed (step S503). .

  In this state, after a predetermined time has passed, the pressure detector 7 is used to detect the pressure value P1 of the gas flow path, and whether the pressure value P1 of the pressure detector 7 at this time is equal to or greater than the set value B. Is determined (step S504). This set value B is a reference pressure for determining whether or not the supply pressure of the raw material gas when normalizing the gas flow path is normal. For example, the compression is executed only with the supply pressure of the raw material gas supply source. In the case of the form, a value smaller than the supply pressure of the source gas supply source is set. For example, when city gas is used as the source gas, the standard value of the gas supply pressure of the city gas is in the range of about 1 kPa to 2.5 kPa. A slightly smaller value (for example, 0.80 kPa) may be set. In addition, the predetermined time is set to a time required to press the gas flow path.

  When the pressure value P1 in step S504 is smaller than the set value B (“No” in step S504), it is determined that the supply pressure of the source gas is abnormal (step S505).

  Thereafter, all the valves of the fuel cell system 100 are closed (step S506), an abnormality (gas supply pressure abnormality) is notified using the notification means (step S507), and the inspection ends. This set value B is a reference pressure for determining whether or not the supply pressure of the source gas is normal, and a value smaller than the supply pressure of the source gas source is set. For example, when city gas is used as the raw material gas, the standard value of the gas supply pressure of the city gas is in the range of about 1 kPa to 2.5 kPa, and therefore a value slightly smaller than the minimum value (1 kPa) of the standard value (for example, , 0.80 kPa) may be set.

  On the other hand, when the pressure value P1 is greater than or equal to the set value B (“Yes” in step S504), it is determined that the supply pressure of the source gas is normal. Therefore, in this case, the process proceeds to the next determination step (after step S508).

  First, the source gas main valve 6 is closed (step S508).

  Next, the pressure value P1 of the pressure detector 7 at this time is stored (step S509).

  Next, the second on-off valve 9 is opened (step S510), and is kept in a standby state for a predetermined time (step S511). In this case, if it is assumed that both the first on-off valve 8 and the second on-off valve 9 are not closed and fixed, the first gas passage 4 is opened to the atmosphere via the combustor 2, As a result, the pressure value P2 of the pressure detector 7 should be about atmospheric pressure.

  Thereafter, the pressure value P2 of the pressure detector 7 at this time is stored (step S512).

  Here, using the pressure value P1 in step S509 and the pressure value P2 in step S512, a pressure difference (P1-P2) between them is derived, and whether or not this pressure difference (P1-P2) is equal to or greater than a set value C. Is determined (step S513). This set value C is a reference pressure for determining whether at least one of the first on-off valve 8 and the second on-off valve 9 is stuck, and is set as a value smaller than the set value B. Is done.

  When the pressure difference (P1−P2) in step S513 is smaller than the set value C (in the case of “No” in step S513), the pressure difference is fixed to at least one of the first on-off valve 8 and the second on-off valve 9. Is determined to have occurred (step S514). For example, when the first on-off valve 8 is closed and stuck, in step S510, the source gas supply path 18 on the upstream side of the first on-off valve 8 is not opened to the atmosphere but remains in the closed space. Therefore, in this case, the pressure difference (P1−P2) is smaller than the set value C.

  Thereafter, all the valves of the fuel cell system 100 are closed (step S515), an abnormality (open / close valve sticking abnormality) is notified using the notification means (step S516), and the inspection is completed.

  On the other hand, when the pressure difference (P1−P2) in step S513 is equal to or larger than the set value C (“Yes” in step S513), the first on-off valve 8 and the second on-off valve 9 are stuck. It is determined that it has not been performed, and no abnormality is reported, and all the valves of the fuel cell system 100 are closed (step S517), and the inspection ends.

  As described above, in the fuel cell system 100 according to the present embodiment, the first on-off valve 8 and the second on-off valve 9 are adhered to the pressure detector as shown in the operation flow of the on-off valve adhesion inspection shown in FIG. 7 can be known from the pressure difference (P1−P2) before and after the opening / closing of the second opening / closing valve 9 using 7.

(Embodiment 3)
The fuel cell system according to Embodiment 3 performs a pressure-compensating operation that is performed after the generation operation of the hydrogen-containing gas in the reformer is stopped when a gas leak in the second gas flow path is detected by the gas leak tester. You may provide the supplementary pressure operation prohibitor to prohibit.

  With such a configuration, it is possible to prevent the pressure compensation operation from being performed unnecessarily even though there is a possibility that the pressure cannot be compensated for the reformer due to gas leakage in the second gas flow path.

  Further, when the sticking inspector is detected by the sticking tester, a supplementary pressure operation prohibiting unit that prohibits a supplementary pressure operation that is performed after the operation of generating the hydrogen-containing gas in the reformer may be provided.

  With such a configuration, it is possible to prevent the pressure compensation operation from being performed wastefully even though there is a possibility that the pressure on the reformer cannot be compensated due to the fixing of the on-off valve.

  Here, the pressure compensation operation of the reformer refers to a gas (for example, for example, in the reformer when the internal pressure of the sealed reformer decreases after the hydrogen-containing gas generation operation of the reformer is stopped). It refers to an operation that compensates for a decrease in internal pressure of the reformer by injecting a raw material gas). More specifically, when the supply of the raw material gas and water to the reformer 1 is stopped and the generation operation of the hydrogen-containing gas is stopped, the first on-off valve 8 and the second on-off valve 9 are closed. The reformer is sealed. Thereafter, the internal pressure of the reformer decreases as the temperature of the reformer decreases. However, the raw material gas is supplied to the reformer 1 by opening the source gas main valve 6 and the first on-off valve 8 in response to the decrease in internal pressure. Supplyed and supplemented. Note that the above operation is an example, and the form thereof is arbitrary as long as it is possible to supplement the reformer whose internal pressure has decreased.

  Here, the supplemental pressure operation prohibitor includes, for example, an arithmetic processing unit that executes a control program related to the supplemental pressure prohibition operation, and a storage unit that stores the control program.

  FIG. 7 is a flowchart showing an example of the supplemental pressure prohibition control by the fuel cell system of the present embodiment.

  A program for executing each operation flow shown in FIG. 7 is stored in a storage unit (not shown) of the controller 17. Here, the controller 17 functions as a gas leak tester, a sticking tester, and a pressure compensation operation prohibitor. Then, the above program is read out to an arithmetic processing unit (not shown) of the controller 17 at an appropriate time (for example, when the fuel cell system 100 is stopped), and this program performs the following operations of the fuel cell system 100. Execute while controlling each part.

  First, a gas leak inspection is performed in the second gas flow path 12 (step S401), and it is determined whether or not a gas leak has occurred in the second gas flow path 12 (step S402). A specific inspection method (procedure and determination method) for gas leakage in the second gas flow path 12 has been described in the operation flow of FIG. Therefore, the description is omitted.

  When it is determined that there is an abnormality (gas leakage) in the second gas flow path 12 (in the case of “No” in step S402), the abnormality (gas leakage) is notified using the notification means (step S407). Then, the pressure compensation operation of the reformer 1 is prohibited (step S408), and the inspection is completed.

  On the other hand, when it is determined that there is no abnormality (gas leakage) in the second gas flow path 12 (“Yes” in step S402), the process proceeds to the next inspection and determination step, and the first on-off valve 8 and the first 2 is checked (step S403), and it is determined whether at least one of the first on-off valve 8 and the second on-off valve 9 is stuck (step S404). . The specific adhesion inspection method (procedure and determination method) of the first on-off valve 8 and the second on-off valve 9 has been described in the operation flow of FIG. Therefore, the description is omitted.

  When it is determined that at least one of the first on-off valve 8 and the second on-off valve 9 has an abnormality (on-off valve sticking) (in the case of “No” in step S404), an abnormality ( The on / off valve sticking) is notified (step S407), the pressure compensation operation of the reformer 1 is prohibited (step S408), and the inspection ends.

  As described above, in the fuel cell system 100 of the present embodiment, when a gas leak in the second gas passage 12 is detected as in the operation flow shown in FIG. The compensation operation performed after the generation operation is stopped is prohibited by using the compensation operation prohibitor 17C. Further, when it is detected that the on-off valve is stuck, the pressure compensation operation performed after the hydrogen-containing gas generating operation of the reformer 1 is stopped is prohibited.

  In the above operation flow, even when it is determined that there is an abnormality (gas leak) in the gas leak inspection of the second gas passage 12, at least one of the first on-off valve 8 and the second on-off valve 9 is provided. Even when it is determined that there is an abnormality (open / close valve sticking), the pressure compensation operation is prohibited, but the present invention is not limited to this.

  For example, when it is determined in the gas leak inspection of the second gas flow path 12 that there is an abnormality (gas leakage), and at least one of the first on-off valve 8 and the second on-off valve 9 is abnormal (the on-off valve) In the case where it is determined that there is (fixation), a mode in which the pressure compensation operation is prohibited may be adopted.

  Further, the fuel cell system of the present embodiment adopts a form in which the on / off valve sticking inspection is executed, but in the form in which the sticking inspection is not executed as in the first embodiment and its modification, the second When it is determined that there is an abnormality in the gas leak inspection of the gas flow path, a form of prohibiting the pressure compensation operation of the reformer may be adopted.

  In the fuel cell systems according to the first to third embodiments, the examples, and the modified examples, the gas leak inspection and the sticking inspection determine the presence or absence of gas leak and the presence or absence of sticking based on the detected pressure of the pressure detector 7. However, the present invention is not limited to this, and the detection value of any detector may be used as long as the above inspection can be performed. For example, a raw material gas flow meter is provided upstream of the branch point of the raw material gas supply passage 18 to the combustion fuel passage 20, and at least one of a gas leak inspection and a sticking inspection is performed based on the flow rate value measured by the flow meter. It is possible to adopt a form for executing the above. In the case of this form, in the gas leak test, for example, it is determined that a gas leak has occurred when a flow rate equal to or higher than a predetermined threshold value is measured with a flow meter after execution of compression. Further, in the sticking inspection, for example, when the measured value of the flow meter is less than a predetermined threshold after the second on-off valve is opened after performing the tensioning, it is determined that sticking has occurred.

  Further, in the compression operation performed in the fuel cell systems of the first to third embodiments, the examples, and the modified examples, the source gas source valve 6 supplies the source gas to the first gas channel and the second gas channel. It functions as a raw material gas supply device. However, in the pressing operation, a source gas is supplied to the gas flow path using a booster (not shown) provided in the source gas supply path 18 and a predetermined pressure higher than the supply pressure of the source gas supply source is used. It is also possible to adopt a form in which the pressure is increased to. In the case of this form, the source gas main valve 6 and the booster function as a source gas supply device.

  Further, in the gas leak inspection of the first gas flow path executed in the fuel cell systems of the first to third embodiments, the examples, and the modified examples, the second on-off valve 9 to be closed is the first gas flow As long as at least the most downstream opening / closing valve (for example, 9A, 9C) is closed in the path, the opening / closing operation of the other opening / closing valves is arbitrary. For example, when the second on-off valves 9A, 9B, and 9C are closed and the gas leakage inspection is performed, the gas leakage in the first gas passage including the bypass gas passage 4A is inspected. When the second on-off valve 9A and 9C is closed and the second on-off valve 9B is opened to perform a gas leak test, the first on-off valve 4A and the anode gas passage 4B are included. The gas flow path is inspected for gas leaks.

  According to the present invention, a fuel cell system having an assist combustion path can provide a fuel cell system in which errors in a gas leak inspection are reduced as compared with a conventional fuel cell system.

DESCRIPTION OF SYMBOLS 1 Reformer 2 Combustor 3 Fuel cell 4 1st gas flow path 6 Raw material gas main valve 7 Pressure detector 8 1st on-off valve 9 2nd on-off valve 12 2nd gas flow path 13 3rd on-off Valve (sealing mechanism)
14 Water supplier 15 Air supplier 16 Oxidant gas supplier 17 Controller 18 Raw material gas supply channel 19 Water supply channel 20 Combustion fuel channel 100 Fuel cell system

Claims (8)

A reformer that generates a hydrogen-containing gas by a reforming reaction using a raw material gas;
A combustor for heating the reformer;
A first gas flow path through which the raw material gas flowing into the reformer flows;
A second gas flow path through which a raw material gas that bypasses the reformer and flows into the combustor flows;
A fuel cell that generates electricity using the hydrogen-containing gas;
The source gas is supplied to the second gas channel before the source gas is supplied to the first gas channel and the gas leak in the first gas channel is inspected. A gas leak tester for inspecting gas leaks of
A fuel cell system comprising: A first on-off valve provided in a first gas flow path upstream of the reformer;
A second on-off valve provided in a first gas flow path downstream of the first on-off valve;
A sealing mechanism provided in the second gas flow path,
The gas leak tester closes the first on-off valve and the second on-off valve and seals the second gas flow path with the sealing mechanism, and the source gas is supplied to the second on-off valve. The fuel cell system according to claim 1, wherein a gas leak in the second gas flow path is inspected by supplying the gas flow path.   The gas leak tester closes the second on-off valve and seals the second gas channel with the sealing mechanism, and the first gas channel and the second gas channel. 3. The fuel cell system according to claim 2, wherein after supplying the raw material gas, the first on-off valve is closed to check for gas leakage in the second gas flow path.   The gas leak tester, when performing the gas leak test of the first gas flow path after the gas leak test of the second gas flow path, prior to the test, the first on-off valve and the The fuel cell system according to claim 3, further comprising a sticking tester that performs a sticking test of the second on-off valve.   5. The fuel cell system according to claim 4, wherein the sticking tester performs the sticking test after opening the first gas flow path to the atmosphere. A pressure detector for detecting the supply pressure of the source gas;
The sticking tester is
(I) After closing the first on-off valve and the second on-off valve, while supplying the raw material gas, open the first on-off valve and the second on-off valve in this order,
(Ii) The fuel cell system according to claim 5, wherein the adhesion is inspected based on a pressure difference detected by the pressure detector before and after opening the second on-off valve.   When a gas leak in the second gas flow path is detected by the gas leak tester, a pressure compensation operation prohibitor that prohibits a pressure compensation operation performed after the hydrogen-containing gas generation operation of the reformer is stopped. The fuel cell system according to claim 1, comprising:   5. The fuel according to claim 4, further comprising a supplemental pressure operation prohibitor that prohibits a supplementary pressure operation that is performed after the hydrogen-containing gas generation operation of the reformer is stopped when the adhesion is detected by the adhesion inspection device. Battery system.

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