JP2012079605A - Fuel cell system - Google Patents

Abstract

Provided is a fuel cell system for performing a failure diagnosis of a valve provided with a raw fuel flow path at the time of a leakage diagnosis of a raw fuel in a stopped state where the fuel cell system is not operating.
A fuel cell system (1) includes a fuel cell (2), a hydrogen generator (3), and a controller (19). The controller (19) is in a stopped state in which the fuel cell (2) and the hydrogen generator (3) are stopped. Then, the sticking inspection for detecting whether or not the second valve 9 and the fourth valve 15 are opened in response to the opening command is performed, and the sticking inspection of the valve and the valve open failure inspection are executed at the time of diagnosing raw fuel leakage .
[Selection] Figure 1

Description

  The present invention relates to a fuel cell system for diagnosing a leakage of a raw fuel gas path of a fuel cell system and an abnormality of a valve provided in the raw fuel gas path.

  A fuel cell is a device that generates water and heat by generating electricity through an electrochemical reaction between a fuel gas containing hydrogen and an oxidant gas containing oxygen. Fuel cells have high power generation efficiency because they can be directly extracted as electrical energy without converting the chemical energy of the fuel into mechanical energy.

  As a conventional general fuel cell system, there is one represented by the configuration of FIG. 10 (see, for example, Patent Document 1).

  As shown in FIG. 10, the fuel cell system 201 burns unreacted fuel gas discharged from the fuel cell, a hydrogen generator 203 that generates fuel gas containing hydrogen supplied to the fuel cell 202 as fuel. The combustor 203a of the hydrogen generator 203 to be reused, the raw material gas passage 205 supplied to the hydrogen generator 203 and connected to the raw material gas infrastructure 204, and the pressure detector 206 for detecting the pressure in the raw material gas passage 205 A source gas main valve 207 arranged on the upstream side of the pressure detector 206 in the source gas flow path 205 to cut off / open the source gas supply, source gas supply means 208 for supplying source gas, source gas A raw material gas supply valve 209 is disposed upstream of the hydrogen generator 203 and downstream of the pressure detector 206 in the flow path 205 to shut off / open the supply of the raw material gas, and the raw material gas flow path 205. The hydrogen gas is generated by a branch flow path 210 that branches from the inlet side of the raw material gas supply valve 209 and supplies the raw material gas to the combustor 203 a, a raw material gas branch valve 211 disposed on the branch flow path 210, and the hydrogen generator 203. A fuel gas passage 212 for introducing the fuel gas into the fuel cell 202 is provided. Furthermore, an exhaust gas passage 213 for guiding the fuel gas from the fuel cell 202 to the combustor 203a, a bypass passage 214 for bypassing the fuel cell 202 and connecting the fuel gas passage 212 and the exhaust gas passage 213, Disposed between the fuel cell 202 from a branch point between the bypass valve 215 for communicating / blocking the bypass passage 214 disposed on the bypass passage 214 and the bypass passage 214 on the fuel gas passage 212. An air supply means for supplying combustion air to the combustor 203a, an anode inlet valve 216, an anode outlet valve 217 disposed between the junctions of the fuel cell 202 and the bypass passage 214 on the exhaust gas passage 213 As an air blower 218 and a controller for controlling the operation of each device constituting the fuel cell system 201.

JP 2008-108446 A

  However, in the configuration of the conventional fuel cell system, only the leakage of the raw fuel gas passage is diagnosed, and the abnormality of the valve provided in the raw fuel gas passage is not diagnosed.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a fuel cell system that performs a failure diagnosis of a valve provided in a raw fuel flow path at the time of a raw fuel leak diagnosis. .

In order to achieve the conventional problem, a fuel cell system of the present invention includes:
A hydrogen generator for generating a fuel gas containing hydrogen from a raw material gas and water vapor by a reforming reaction;
A fuel cell that generates electricity using a fuel gas containing hydrogen and an oxidant gas containing oxygen;
A source gas flow path that is supplied to the hydrogen generator and connected to the source gas infrastructure;
A pressure detector for detecting the pressure in the source gas flow path;
A first valve disposed upstream of the pressure detector in the source gas flow path;
A second valve disposed upstream of the hydrogen generator and downstream of the pressure detector in the source gas flow path;
A branch channel that branches from between the second valve and the hydrogen generator in the source gas channel;
A third valve arranged on the branch flow path;
A fuel gas flow path for introducing the fuel gas generated by the hydrogen generator into the fuel cell;
An exhaust gas flow path for discharging fuel gas from the fuel cell;
A bypass passage that bypasses the fuel cell and connects the fuel gas passage and the exhaust gas passage;
A fourth valve arranged on the bypass flow path;
A fifth valve disposed between the branch point of the bypass path on the fuel gas path and the fuel cell;
A sixth valve disposed on the exhaust gas flow path between the joining points of the fuel cell and the bypass flow path on the exhaust gas flow path;
A fuel cell system comprising a controller,
As a sticking test for detecting whether or not the second valve and the fourth valve are opened in response to the opening command in a state where the hydrogen generator and the fuel cell are stopped,
(1) After closing the first to sixth valves, the first valve and the second valve are opened to supply the raw material gas, and the first pressure is detected by the pressure detector in the state where the first valve is closed,
(2) When the second pressure is detected by the pressure detector after the fourth valve is opened and the first pressure and the second pressure are not equal, the second valve and the fourth valve are determined to be normal. ,
(3) When the first pressure and the second pressure are equal, it is determined that the second valve and the fourth valve are abnormal,
(4) After the first to sixth valves are closed, the first valve and the second valve are opened to supply the raw material gas, and the third pressure is detected by the pressure detector in the state where the first valve is closed,
(5) When the fourth pressure is detected by the pressure detector after the third valve is opened, and the third pressure and the fourth pressure are not equal, the fourth valve is determined to be abnormal,
(6) When the third pressure and the fourth pressure are equal, the second valve is determined to be abnormal.

  Thus, by determining that the second valve is abnormal, it is possible to determine whether the second valve or the fourth valve is stuck abnormally with the pressure detector provided in the raw material path, and that the second valve or the fourth valve is stuck abnormally. When the determination is made, it is possible to determine whether the second valve is fixed or the fourth valve is fixed by using the third valve of the bypass flow path branched from the outlet of the second valve. Along with the gas path leakage inspection, it is possible to perform failure diagnosis of the shutoff valve provided in the raw fuel path.

  In the fuel cell system of the present invention, in a state where the hydrogen generator and the fuel cell are not in operation, in addition to the leakage inspection of the raw fuel gas flow path, the failure diagnosis of the valve provided with the raw fuel path is also performed. It can be done.

1 is a block diagram showing an outline of a fuel cell system in Embodiment 1 of the present invention. The flowchart which shows a series of operation | movement of the sticking test | inspection of the valve | bulb of the fuel cell system in Embodiment 1 of this invention. The flowchart which shows a series of operation | movement of the leak test | inspection of the fuel cell system in Embodiment 1 of this invention. The flowchart which shows a series of operation | movement of the valve open fault test | inspection of the fuel cell system in Embodiment 1 of this invention. Block diagram showing an outline of a fuel cell system according to Embodiment 2 of the present invention. FIG. 5 is a flowchart showing a series of operations for valve sticking inspection of the fuel cell system according to Embodiment 2 of the present invention. FIG. 7 is a flowchart showing a series of operations for a leak test of a fuel cell system according to Embodiment 2 of the present invention. The flowchart which shows a series of operation | movement of the valve open fault test | inspection of the fuel cell system in Embodiment 2 of this invention. FIG. 7 is a flowchart showing a series of operations for a leak test of a fuel cell system according to Embodiment 2 of the present invention. Block diagram showing outline of conventional fuel cell system

The first invention is
A hydrogen generator for generating a fuel gas containing hydrogen from a raw material gas and water vapor by a reforming reaction;
A fuel cell that generates electricity using a fuel gas containing hydrogen and an oxidant gas containing oxygen;
A source gas flow path that is supplied to the hydrogen generator and connected to the source gas infrastructure;
A pressure detector for detecting the pressure in the source gas flow path;
A first valve disposed upstream of the pressure detector in the source gas flow path;
A second valve disposed upstream of the hydrogen generator and downstream of the pressure detector in the source gas flow path;
A branch channel that branches from between the second valve and the hydrogen generator in the source gas channel;
A third valve arranged on the branch flow path;
A fuel gas flow path for introducing the fuel gas generated by the hydrogen generator into the fuel cell;
An exhaust gas passage for releasing the fuel gas from the fuel cell to the atmosphere and discharging;
A bypass passage that bypasses the fuel cell and connects the fuel gas passage and the exhaust gas passage;
A fourth valve arranged on the bypass flow path;
A fifth valve disposed on the fuel gas flow path between the junction of the exhaust gas flow path and the bypass flow path from the branch point with the bypass flow path on the fuel gas flow path;
A sixth valve disposed on the exhaust gas flow path between the branch point of the bypass flow path on the fuel gas flow path and the junction of the exhaust gas flow path and the bypass flow path;
A fuel cell system comprising a controller,
As a sticking test for detecting whether or not the second valve and the fourth valve are opened in response to the opening command in a state where the hydrogen generator and the fuel cell are stopped,
(1) After closing the first to sixth valves, the first valve and the second valve are opened to supply the raw material gas, and the first pressure is detected by the pressure detector in the state where the first valve is closed,
(2) When the second pressure is detected by the pressure detector after the fourth valve is opened and the first pressure and the second pressure are not equal, the second valve and the fourth valve are determined to be normal. ,
(3) When the first pressure and the second pressure are equal, it is determined that the second valve and the fourth valve are abnormal,
(4) After the first to sixth valves are closed, the first valve and the second valve are opened to supply the raw material gas, and the third pressure is detected by the pressure detector in the state where the first valve is closed,
(5) When the fourth pressure is detected by the pressure detector after the third valve is opened, and the third pressure and the fourth pressure are not equal, the fourth valve is determined to be abnormal,
(6) By determining that the second valve is abnormal when the third pressure and the fourth pressure are equal,
If the pressure detector provided in the raw material path can determine whether the second valve or the fourth valve is stuck abnormally, and if the second valve or the fourth valve is judged to be stuck abnormally, it is branched from the outlet of the second valve. By using the third valve of the bypass flow path, it can be determined whether the second valve is fixed or the fourth valve is fixed.

The second invention is particularly the fuel cell system according to the first invention,
The raw material gas flow path includes a raw material supply amount detection means for detecting the supply amount of the raw material gas,
As a sticking test for detecting whether or not the second valve and the fourth valve are opened in response to an opening command in a state where the operation of the hydrogen generator and the fuel cell is stopped,
(1) After the first to sixth valves are closed, the first valve and the second valve are opened to supply the raw material gas, the first valve is closed, and the raw material is supplied immediately after the fourth valve is opened. When the first raw material supply amount is detected by the amount detection means, and the first raw material supply amount is larger than the specified value, it is determined that the second valve and the fourth valve are normal, and (2) the first raw material supply amount is When less than the specified value, it is judged that the second valve and the fourth valve are abnormal,
(3) After closing the sixth valve from the first valve, opening the first valve and the second valve and supplying the raw material gas, then closing the first valve and further opening the third valve When the second raw material supply amount by the raw material supply means is detected and the second raw material supply amount is less than the specified value, it is determined that the fourth valve is abnormal,
(4) By determining that the second valve is abnormal when the second raw material supply amount is greater than the specified value,
Abnormal sticking abnormality can be detected not by the pressure detector but by the raw material supply amount detection means.

The third aspect of the invention is particularly the fuel cell system of the first aspect of the invention,
After performing the sticking test, the controller is in a state where the hydrogen generator and the fuel cell are stopped, and as a leak test of the flow path from the first valve to the fourth valve and the sixth valve,
(1) The first to sixth valves are closed, the first valve, the second valve, and the fifth valve are opened. After supplying the raw material gas, the first valve is closed and the first valve is closed immediately after the first valve is closed. Detecting the first pressure by the pressure detector; (2) detecting the second pressure by the pressure detector after a predetermined time has elapsed since the first valve was closed; Are determined to be normal, the flow paths from the first valve to the fourth valve and the fifth valve are normal,
(3) When the first pressure and the second pressure are not equivalent, the first to sixth valves are closed, the first valve and the second valve are opened, and the source gas is supplied, and then the first valve is turned on. Close and detect the third pressure by the pressure detector immediately after the first valve is closed,
(4) When the fourth pressure is detected by the pressure detector after a predetermined time has elapsed since the first valve was closed, and the third pressure and the fourth pressure are equal, the fifth valve to the sixth valve Judging that the valve flow path is abnormal,
(5) When the third pressure and the fourth pressure are not equal, the first to sixth valves are closed, the first valve and the fourth valve are opened and the raw material gas is supplied, and then the first valve is turned on. Close and detect the fifth pressure by the pressure detector immediately after the first valve is closed,
(6) When the sixth pressure is detected by the pressure detector after a lapse of a predetermined time after the first valve is closed and the fifth pressure and the sixth pressure are equal, the second valve to the fourth The flow path of the valve and the fifth valve is judged abnormal,
(7) By determining that the flow path from the first valve to the second valve is abnormal when the fifth pressure and the sixth pressure are not equivalent,
Since the leak inspection is executed after determining the valve sticking abnormality necessary for the leak inspection, it is possible to reduce detection errors of the leak abnormality. Moreover, when the flow path from the 1st valve to the 4th valve and the 6th valve is leaking, the leak location can be specified.

In particular, the fourth invention is the fuel cell system of the first or second invention,
After performing the sticking test, the controller is in a state where the hydrogen generator and the fuel cell are stopped, and as a leak test of the flow path from the first valve to the fourth valve and the sixth valve,
(1) The first to sixth valves are closed, the first valve, the second valve, and the fifth valve are opened to supply the raw material gas, and then the first raw material supply amount by the raw material supply amount detection means is set. And when the first raw material supply amount is less than the specified value, the flow paths of the first valve to the fourth valve and the fifth valve are determined to be normal,
(2) When the first raw material supply amount is larger than the specified value, the first to sixth valves are closed, the first valve and the second valve are opened, and the raw material gas is supplied. When the second raw material supply amount is detected and the second raw material supply amount is less than the specified value, it is determined that the flow path from the fifth valve to the sixth valve is abnormal,
(3) When the second raw material supply amount is larger than the specified value, the first to sixth valves are closed, the first valve and the fourth valve are opened to supply the raw material gas, and then the raw material supply amount detection means When the third raw material supply amount is detected and the third raw material supply amount is less than the specified value, it is determined that the flow paths from the second valve to the fourth valve and the fifth valve are abnormal,
(4) By determining that the flow path from the first valve to the second valve is abnormal when the third raw material supply amount is greater than the specified value,
Leakage can be detected not by the pressure detector but by the raw material supply amount detection means.

The fifth aspect of the invention is particularly the fuel cell system of the first or second aspect of the invention,
A housing that houses at least a hydrogen generator, a fuel cell, and a controller;
Provided with flammable gas detection means for detecting flammable gas in the housing,
After performing the sticking test, the controller is in a state where the hydrogen generator and the fuel cell are stopped, and as a leak test of the flow path from the first valve to the fourth valve and the sixth valve,
(1) After the first to sixth valves are closed, the first valve, the second valve, and the fifth valve are opened and the raw material gas is supplied, the first combustible gas concentration by the combustible gas detection means When the first combustible gas concentration is lower than the specified value, it is determined that the flow paths from the first valve to the fourth valve and the fifth valve are normal,
(2) When the first combustible gas concentration is higher than the specified value, the first to sixth valves are closed, the first valve and the second valve are opened, and the raw material gas is supplied, and then the combustible gas detection means When the second combustible gas concentration is detected and when the second combustible gas concentration is lower than the specified value, it is determined that the flow path from the fifth valve to the sixth valve is abnormal,
(3) When the second combustible gas concentration is higher than the specified value, the first to sixth valves are closed, the first valve and the fourth valve are opened, and the raw material gas is supplied, and then the combustible gas detection means When the third combustible gas concentration is detected by, and when the third combustible gas concentration is lower than the specified value, it is determined that the flow paths from the second valve to the fourth valve and the fifth valve are abnormal,
(4) By determining that the flow path from the first valve to the second valve is abnormal when the third combustible gas concentration is higher than the specified value,
Leakage can be detected by the combustible gas detection means provided in the housing.

The sixth aspect of the invention is particularly the fuel cell system according to any one of the third to fifth aspects of the invention.
The controller detects whether or not the second valve and the fifth valve are closed in response to the closing command in a state where the hydrogen generator and the fuel cell are stopped after the leakage inspection is performed. As
(1) After the first to sixth valves are closed, the first valve and the fourth valve are opened and the raw material gas is supplied, the first valve is closed, and the pressure detector immediately after the first valve is closed 1 pressure is detected,
(2) The second pressure is detected by the pressure detector after a predetermined time has elapsed since the first valve was closed, and the second valve is judged to be abnormal when the first pressure and the second pressure are not equal. And
(3) When the first pressure and the second pressure are equal, the fourth valve is closed, the first valve, the second valve, and the sixth valve are opened and the raw material gas is supplied. Close the valve, detect the third pressure by the pressure detector immediately after the first valve closes,
(4) When the fourth pressure is detected by the pressure detector after a lapse of a predetermined time since the first valve is closed, and the third pressure and the fourth pressure are not equal, the fourth valve is determined to be abnormal. And
(5) When the third pressure and the fourth pressure are not equal, by determining that the fourth valve is normal,
Since the valve open failure inspection is executed after performing the leak inspection necessary for the valve open failure inspection, detection errors in the open failure inspection can be reduced.

The seventh invention is particularly the fuel cell system of any one of the first to fifth inventions,
The controller detects whether or not the second valve and the fifth valve are closed in response to the closing command in a state where the hydrogen generator and the fuel cell are stopped after the leakage inspection is performed. As
(1) After the first to sixth valves are closed, the first valve and the fourth valve are opened and the raw material gas is supplied, the first raw material supply amount is detected by the raw material supply amount detection means, and the first When the raw material supply amount is larger than the specified value, the second valve is judged to be abnormal,
(2) When the first raw material supply amount is lower than the specified value, the fourth valve is closed, the first valve, the second valve and the sixth valve are opened to supply the raw material gas, and then the raw material supply amount detection means When the second raw material supply amount is detected and the second raw material supply amount is larger than the specified value, the fourth valve is determined to be abnormal,
(3) By determining that the fourth valve is normal when the second raw material supply amount is less than the specified value,
Since the valve open failure inspection is executed after performing the leak inspection necessary for the valve open failure inspection, detection errors in the open failure inspection can be reduced. In addition, the valve open failure inspection can be performed not by the pressure detection means but by the raw material supply amount detection means.

The eighth invention is particularly the fuel cell system of the first or second invention,
A housing that houses at least a hydrogen generator, a fuel cell, and a controller;
Provide ventilation means to vent the atmosphere gas in the housing,
The controller operates the ventilation means when performing at least one of a sticking test, a leak test, and an open fault test,
By suppressing the flammable gas concentration leaking from the inside of the casing to below the flammable range, even if gas leaks at the time of inspection, it can be diluted and discharged to the outside of the flammable range by the ventilation operation by the ventilation means, which is preferable in terms of safety.

The ninth aspect of the invention is particularly the fuel cell system according to any one of the first to seventh aspects of the invention,
A combustor for heating the hydrogen generator;
Air supply means for supplying combustion air to the combustor;
The exhaust gas flow path is led to the combustor,
The controller operates the air supply means at the time of performing at least one of a sticking test, a leak test, and an open fault test,
By controlling the concentration of the raw material gas discharged from the combustor below the flammable range, even if gas leaks downstream of the exhaust gas flow path at the time of inspection, it can be diluted and discharged below the flammable range by the air supply means. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a block diagram schematically showing the configuration of the fuel cell system according to Embodiment 1 of the present invention. The fuel cell system 1 in this embodiment includes a fuel cell 2 that generates power using a fuel gas containing hydrogen and an oxidant gas containing oxygen, and a fuel gas containing hydrogen by a reforming reaction from a raw material gas and water vapor. The generated hydrogen generator 3, the combustor 3 a of the hydrogen generator 3, the source gas channel 5 supplied to the hydrogen generator 3 and connected to the source gas infrastructure 4, and the pressure in the source gas channel 5 are detected. Pressure detector 6, source gas source valves 7 a, 7 b as a first valve arranged upstream of the pressure detector 6 in the source gas flow path 5 to shut off / open the source gas supply, source gas flow A raw material gas blower 8 serving as a raw material supply means for supplying a raw material gas to the hydrogen generator 3 disposed on the path 5 and a raw material gas flow path 5 disposed upstream of the hydrogen generator 3 and downstream of the pressure detector 6. As a second valve to shut off / open the supply As a gas supply valve 9, a branch passage 10 that branches from the source gas supply valve 9 and the hydrogen generator 3 in the source gas passage 5, and a third valve inside the hydrogen generator arranged on the branch passage A source gas branch valve 11 is provided. Also, a fuel gas passage 12 for introducing the fuel gas generated by the hydrogen generator 3 into the fuel cell 2, and an exhaust gas passage for discharging the fuel gas from the fuel cell 2 to the atmosphere via the combustor 3a. 13, for bypassing the fuel cell 2 and connecting the fuel gas passage 12 and the exhaust gas passage 13 to each other and the bypass passage 14 disposed on the bypass passage 14 to communicate / block. As the fourth valve, the anode inlet valve 16 as the fifth valve disposed between the fuel cell 2 from the branch point of the bypass valve 15 and the bypass passage 14 on the fuel gas passage 12, and the exhaust gas passage 13 An anode outlet valve 17 is provided as a sixth valve arranged between the upper fuel cell 2 and the bypass flow path 14 and an air blower 18 is provided as air supply means for supplying combustion air to the combustor 3a. ing. Furthermore, a controller 19 that controls the operation of each device constituting the fuel cell system 1, a fuel cell 2, a hydrogen generator 3, a combustor 3 a, a raw material gas channel 5, a branch channel 10, and a fuel gas channel 12. The exhaust gas flow path 13, the bypass flow path 14, the air blower 18, and the controller 19 are provided with a housing 20, and a ventilation fan 21 is provided as a ventilation means for ventilating the atmospheric gas in the housing.

  Here, the controller 19 includes at least the source gas source valves 7a and 7b, the source gas supply valve 9, the source gas branch valve 11, the bypass valve 15, the anode inlet valve 16, the anode outlet valve 17, the air blower 18, and the ventilation fan. 21 is controlled.

  A series of specific operations relating to leakage inspection and valve failure diagnosis of the fuel cell system 1 in the present embodiment will be described. FIG. 2 is a series of operational flow charts of the fuel cell system valve sticking inspection in the first embodiment of the present invention, and FIG. 3 is a series of operational flow charts of the fuel cell system leakage inspection in the first embodiment of the present invention. FIGS. 4A and 4B are a series of operation flowcharts for the valve open failure inspection of the fuel cell system according to Embodiment 1 of the present invention.

  First, when a command for leakage inspection and valve failure diagnosis is output from the controller 19 while the fuel cell 2 and the hydrogen generator 3 are stopped, as shown in FIG. After closing the valve (step S101), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S102), and the gas is supplied to the source gas flow path 5 and the hydrogen generator 3. Here, when the pressure value P1 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S103), the raw material gas main valves 7a and 7b are closed (step). The pressure value P1 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 together with S104) (step S105). Then, the bypass valve 15 is opened (step S106), the source gas flow path 5 and the hydrogen generator 3 are opened to the atmosphere, and the gas supplied to the source gas flow path 5 and the hydrogen generator 3 in step S102 is sufficient. After elapse of the first predetermined time (for example, 30 seconds), the pressure value P2 detected by the pressure detector 6 is detected (step S107), and the difference between the pressure values P1 and P2 is equal to or greater than the second threshold value B. Is determined (step S108).

  When it is determined that the difference between the pressure value P1 and the pressure value P2 is not equal to or greater than the second threshold value B and the pressure value P1 is equal to the pressure value P2, the material gas supply valve 9 or the bypass valve 15 is abnormally stuck. Then, the process proceeds to the next step S109. This is because if the source gas supply valve 9 or the bypass valve 15 is not fixed, the pressure value detected by the pressure detector should be reduced to the atmospheric pressure when the atmosphere is released in step S106. It does not decrease because it is estimated that either the source gas supply valve 9 or the bypass valve 15 is fixed.

  Next, in order to diagnose whether the fixed valve is the source gas supply valve 9 or the bypass valve 15, once all the valves are closed (step S109), the source gas source valves 7a and 7b and the source gas The gas supply valve 9 is opened (step S110), and gas is supplied to the source gas flow path 5 and the hydrogen generator 3. Here, when the pressure value P3 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in Step S111), the raw material gas main valves 7a and 7b are closed (Step). At the same time, the pressure value P3 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 (step S113). Then, the source gas branch valve 11 is opened (step S114), the source gas channel 5 and the hydrogen generator 3 are opened to the atmosphere, and the gas supplied to the source gas channel 5 and the hydrogen generator 3 in step S110 After a sufficiently long second predetermined time (for example, 30 seconds) has passed, the pressure value P4 detected by the pressure detector 6 is detected (step S115), and the difference between the pressure values P3 and P4 is greater than or equal to the second threshold B. Is determined (step S116).

  If the difference between the pressure value P3 and the pressure value P4 is equal to or greater than the second threshold value B and the pressure value P1 and the pressure value P2 are not equal, the pressure value detected by the pressure detector reaches the atmospheric pressure. Since it has decreased, it can be determined that the source gas supply valve 9 and the source gas branch valve 11 are operating normally, and the fixed valve is abnormally stopped as being the bypass valve 15 (step 117).

  In addition, when it is determined that the difference between the pressure value P3 and the pressure value P4 is not equal to or greater than the second threshold value B and the pressure value P1 and the pressure value P2 are equal, the pressure value detected by the pressure detector is the atmospheric state. Therefore, it is presumed that the source gas supply valve 9 and the source gas branch valve 11 are fixed. The valve fixed in step S108 is either the source gas supply valve 9 or the bypass valve 15. Therefore, it can be assumed that the fixed valve is the source gas supply valve 9. The controller 19 abnormally stops as an abnormal sticking of the source gas supply valve 9 (step 118).

  Next, in step S108, the difference between the pressure value P1 and the pressure value P2 is equal to or greater than the threshold value B, the pressure value P1 and the pressure value P2 are not equal, and there is no abnormality in fixing the raw material gas supply valve 9 or the bypass valve 15 As a result, adhesion inspection of the anode inlet valve 16 and the anode outlet valve 17 is performed. After all the valves are closed (step S119), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S120), and gas is supplied to the source gas flow path 5 and the hydrogen generator 3. Here, when the pressure value P5 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S121), the raw material gas main valves 7a and 7b are closed (step). The pressure value P5 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 together with S122) (step S123). Then, the anode inlet valve 16 and the anode outlet valve 17 are opened (step S124), and the source gas passage 5, the hydrogen generator 3, the fuel gas passage 12 and the fuel cell 2 are opened to the atmosphere. The pressure value P6 detected by the pressure detector 6 is obtained after a predetermined time (for example, 40 seconds) when the gas supplied to the flow path 5, the hydrogen generator 3, the fuel gas flow path 12 and the fuel cell 2 is sufficiently discharged. It is detected (step S125), and it is determined whether or not it is greater than or equal to the second threshold B (step S126).

  If the difference between the pressure value P5 and the pressure value P6 is equal to or greater than the threshold value B and the pressure value P1 and the pressure value P2 are equal, the anode inlet valve 16 or the anode outlet valve 17 is abnormally stopped as being stuck abnormally ( Step 127). This is because the material gas supply valve 9 is not fixed in step S108, and the fixed valve can be assumed to be the anode inlet valve 16 or the anode outlet valve 17.

  Next, in step S126, when the difference between the pressure value P5 and the pressure value P6 is not equal to or greater than the threshold value B and is not equal to the pressure value P5 and the pressure value P6, the anode inlet valve 16 or the anode outlet valve 17 is stuck abnormally. If not, move on to leak inspection.

  As described above, since the valve sticking abnormality is performed before the leak inspection, the gas can be reliably supplied to the hydrogen generator 3 and the fuel cell 2 at the time of the leak inspection, so that the detection error of the leakage abnormality can be reduced. Here, a series of operation flows regarding leakage inspection of the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12, and the fuel cell 2 will be described with reference to FIG.

  When the controller 19 shifts from the valve sticking test to the leak test, first, after closing all the valves (step S201), the source gas source valves 7a and 7b, the source gas supply valve 9 and the anode inlet valve 16 are opened ( In step S202), gas is supplied to the raw material gas passage 5, the hydrogen generator 3, the fuel gas passage 12, and the fuel cell 2. Here, when the pressure value P1 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S203), the raw material gas main valves 7a and 7b are closed (step). In step S205, the pressure value P1 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 (step S205). Thereafter, the pressure value P2 (step S206) detected by the pressure detector 6 is detected after a predetermined time (for example, after 15 seconds), and the difference between the pressure value P1 and the pressure value P2 is less than the second threshold value B. Is determined (step S207).

  When the difference between the pressure value P1 and the pressure value P2 is not less than the second threshold B and the pressure value P1 and the pressure value P2 are not equal (No in step S207), the source gas source valves 7a and 7b to the bypass valve 15 and Assuming that the flow path to the anode outlet valve 17 is leaking, the process proceeds to the next step S208. If the flow path from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 does not leak, the source gas source valve 7a is closed even if the source gas source valves 7a and 7b are closed in step S204. 7b, the pressure value P1 detected by the pressure detector 6 immediately after closing and the pressure value P2 detected by the pressure detector after a predetermined time should be equal, but the pressure value P1 and the pressure value P2 are not equivalent. This is because it is estimated that any of the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12, the fuel cell 2, the bypass valve 15, and the anode outlet valve 17 is leaking.

  Next, in order to identify the leak location, after closing all the valves (step S208), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S209), and the source gas flow path 5 The gas is supplied to the hydrogen generator 3 and the fuel gas passage 12. Here, when the pressure value P3 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in Step S210), the raw material gas main valves 7a and 7b are closed (Step). In step S212, the pressure value P3 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 (step S212). Thereafter, the pressure value P4 (step S213) detected by the pressure detector 6 is detected after a predetermined time (for example, after 9 seconds), and the difference between the pressure value P3 and the pressure value P4 is less than the second threshold value B. Is determined (step S214).

  When the difference between the pressure value P3 and the pressure value P4 is not less than the second threshold B and the pressure value P3 and the pressure value P4 are equal (Yes in step S214), the source gas source valves 7a and 7b to the anode inlet valve The raw material gas flow path 5, the hydrogen generator 3, and the fuel gas flow path 12 that are the branch flow paths 10 to 16 are not leaking, and the fuel gas flow path that is the flow path from the anode inlet valve 16 to the anode outlet valve 17. 12. It is determined that the fuel cell 2 and the exhaust gas flow path and the anode outlet valve 17 are leaking, and abnormally stops as a leakage abnormality of the flow path from the anode inlet valve 16 to the anode outlet valve 17 (step S215).

  When the difference between the pressure value P3 and the pressure value P4 is not less than the second threshold B and the pressure value P3 and the pressure value P4 are not equal (No in step S214), the source gas source valves 7a and 7b to the bypass valve 15 are used. Assuming that the flow path to the anode outlet valve 17 is leaking, the process proceeds to the next step 216. After all the valves are closed (step S216), the source gas source valves 7a and 7b are opened (step S217), and gas is supplied to the source gas channel 5. Here, when the pressure value P5 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S218), the raw material gas main valves 7a and 7b are closed (step). In step S220, the pressure value P5 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 (step S220). Thereafter, the pressure value P6 (step S221) detected by the pressure detector 6 is detected after a predetermined time (for example, after 3 seconds), and the difference between the pressure value P5 and the pressure value P6 is less than the second threshold value B. It is determined whether or not (step S222).

  When the difference between the pressure value P5 and the pressure value P6 is less than the second threshold value B and the pressure value P5 and the pressure value P6 are equal (Yes in step S222), the source gas source valves 7a and 7b are used as source gas. The raw material gas flow path 5 which is a flow path to the supply valve 9 is not leaking, and the raw material gas flow path 5 which is a flow path from the raw material gas supply valve 9 to the bypass valve 15 and the anode inlet valve 16, the hydrogen generator 3. Then, it is determined that the fuel gas flow path 12 or the bypass flow path 14 is leaking, and abnormally stops as a flow path leakage abnormality from the raw material gas supply valve 9 to the bypass valve 15 and the anode inlet valve 16 (step S223).

The difference between the pressure value P5 and the pressure value P6 is not less than the second threshold B, and the pressure value P5 and the pressure value P6
Are not equivalent (No in step S223), it is determined that the raw material gas passage 5 which is a passage from the raw material gas main valves 7a, 7b to the raw material gas supply valve 9 is leaked, and the raw material gas original valve 7a, Abnormally stops as a leakage of the flow path from 7b to the raw material gas supply valve 9 (step S224).

  Next, when the pressure value P1 and the pressure value P2 are equal in step S207 (Yes in step S207), the flow path from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 does not leak. As a matter of course, it shifts to the valve open failure inspection.

  Since the valve leakage abnormality is executed before the valve open failure inspection, the flow path from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 does not leak during the valve open failure inspection. Therefore, detection errors in the valve open failure inspection can be reduced. Here, a series of operation flows related to the open failure inspection for detecting whether or not the source gas supply valve 9 and the anode inlet valve 16 are closed in response to the closing command will be described with reference to FIG.

  When the controller 19 proceeds from the leak test to the valve open failure test, first, after closing all the valves (step S301), the source gas source valves 7a and 7b and the bypass valve 15 are opened (step S302). Gas is supplied from the source gas source valves 7 a and 7 b to the source gas flow path 5 of the source gas supply valve 9. Here, when the pressure value P1 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S303), the raw material gas main valves 7a and 7b are closed (step). At the same time, the pressure value P1 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 (step S305). Thereafter, the pressure value P2 (step S306) detected by the pressure detector 6 is detected after a predetermined time (for example, 6 seconds), and the difference between the pressure value P1 and the pressure value P2 is less than the second threshold value B. It is determined whether or not (step S307).

  If the difference between the pressure value P1 and the pressure value P2 is not less than the second threshold B (No in step S307), the source gas has passed through the source gas supply valve 9, and the source gas supply valve 9 has failed to open. It is abnormally stopped as being present (step S308).

  When the difference between the pressure value P1 and the pressure value P2 is less than the second threshold B (Yes in step S307), the source gas supply valve 9 is opened because the source gas has not passed through the source gas supply valve 9. There is no failure and the process proceeds to the next step S309. After the bypass valve 15 is closed (step S309), the source gas source valves 7a and 7b, the source gas supply valve 9 and the anode outlet valve 17 are opened (step S310), and the bypass gas 15 and the source gas source valves 7a and 7b are opened. Gas is supplied to the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12, and the bypass flow path 14 to the anode inlet valve 16. Here, when the pressure value P3 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S311), the raw material gas main valves 7a and 7b are closed (step). At the same time, the pressure value P3 detected by the pressure detector 6 is stored in a storage unit (not shown) built in the controller 19 (step S313). Thereafter, the pressure value P4 (step S314) detected by the pressure detector 6 is detected after a predetermined time (for example, after 9 seconds), and the difference between the pressure value P3 and the pressure value P4 is less than the second threshold value B. It is determined whether or not (step S315).

  When the difference between the pressure value P1 and the pressure value P2 is not less than the second threshold value B (No in step S315), the source gas has passed through the anode inlet valve 16 and the anode inlet valve 16 has an open failure. Is abnormally stopped (step S316).

When the difference between the pressure value P3 and the pressure value P4 is not less than the second threshold value B (Yes in step S314), since the source gas has not passed through the anode inlet valve 16, the anode inlet valve 1
6 does not have an open failure, and the valve open adhesion test is terminated.

  In addition, it is preferable to operate the ventilation fan 21 in at least any one of the leak inspection, the valve sticking inspection, and the valve open failure inspection described with reference to FIGS. This is because in this inspection process, there is a possibility that combustible gas may be discharged to the outside of the combustor 3a or the gas flow path. In this case, if the ventilation operation of the ventilation fan 21 is performed, the exhaust is diluted. It is. In addition, it is desirable to set the ventilation amount of the ventilation fan 21 so that the maximum combustible gas concentration leaking from the inside of the casing in the leak inspection and the valve abnormality inspection (sticking inspection and open failure inspection) is less than the combustible range. For example, if the raw material gas in leak inspection and valve abnormality inspection (sticking inspection and open failure inspection) is 13A, and there is a leakage abnormality from piping, etc., the maximum flammable gas concentration leaking from the inside of the housing is Al / min. If there is, the ventilation amount of the ventilation fan 21 is set to 20 Al / min or more so that the concentration of combustible gas leaking from the inside of the casing is less than the lower explosion limit of 13 A.

  In addition, it is preferable to operate the air blower 18 in at least any one of the leakage inspection, the valve sticking inspection, and the valve open failure inspection described with reference to FIGS. 2, 3, and 4. In this inspection process, there is a possibility that combustible gas may be discharged to the outside of the combustor 3a or the gas flow path. In this case, if the ventilation operation of the air blower 18 or the ventilation fan 21 is performed, the dilution is performed. It is because it is discharged. In addition, it is better to set the supply amount of the air blower 18 so that the maximum combustible gas concentration discharged from the combustor 3a in the leak inspection and the valve abnormality inspection (sticking inspection and open failure inspection) is less than the combustible range. desirable. For example, if the raw material gas in the leak inspection and the valve abnormality inspection (sticking inspection and open failure inspection) is 13 A and the maximum combustible gas concentration discharged from the combustor 3 a is Bl / min, the air blower 18 Is set to 20 Bl / min or more so that the concentration of combustible gas leaking from the inside of the housing is less than the lower explosion limit of 13 A.

  In addition, when abnormality is detected among the leak inspection, the valve sticking inspection, and the valve open failure inspection described with reference to FIGS. 2, 3, and 4, it is more preferable to perform abnormality detection a plurality of times. Since an abnormality detection error may occur, it is more preferable that the abnormality is determined and stopped abnormally only after an abnormality is detected a plurality of times.

(Embodiment 2)
FIG. 5 is a block diagram showing an outline of the fuel cell system according to Embodiment 2 of the present invention. The fuel cell system 101 in the present embodiment includes a fuel cell 2 that generates power using a fuel gas containing hydrogen and an oxidant gas containing oxygen, and a fuel gas containing hydrogen by a reforming reaction from a raw material gas and water vapor. The generated hydrogen generator 3, the combustor 3 a of the hydrogen generator 3, the source gas channel 5 supplied to the hydrogen generator 3 and connected to the source gas infrastructure 4, and the pressure in the source gas channel 5 are detected. The pressure detector 6 and the source gas flow meter 22 as a source gas supply means for measuring the source gas supply amount in the source gas channel 5, and the source gas arranged upstream of the pressure detector 6 in the source gas channel 5 Source gas source valves 7a and 7b as first valves for shutting off / opening the supply of gas, and a source gas blower 8 as a source supply means for supplying source gas to the hydrogen generator 3 disposed on the source gas flow path 5, Hydrogen generation in source gas flow path 5 3 and a downstream of the pressure detector 6, a raw material gas supply valve 9 serving as a second valve for shutting off / opening the supply of the raw material gas, and a raw material gas supply valve 9 and a hydrogen generator in the raw material gas flow path 5. 3, a branch flow path 10 that branches from the position 3, and a source gas branch valve 11 as a third valve inside the hydrogen generator disposed on the branch flow path. Further, a fuel gas passage 12 for introducing the fuel gas generated by the hydrogen generator 3 into the fuel cell 2, an exhaust gas passage 13 for guiding the fuel gas from the fuel cell 2 to the combustor 3 a, and bypassing the fuel cell 2 The bypass valve 15 as a fourth valve for communicating / blocking the bypass passage 14 connecting the fuel gas passage 12 and the exhaust gas passage 13 and the bypass passage 14 disposed on the bypass passage 14. And an anode inlet valve 16 as a fifth valve disposed between the fuel cell 2 and a branch point between the fuel gas channel 12 and the bypass channel 14 on the fuel gas channel 12, and a bypass flow from the fuel cell 2 on the exhaust gas channel 13 It has an anode outlet valve 17 as a sixth valve arranged between the junctions with the passage 14 and an air blower 18 as air supply means for supplying combustion air to the combustor 3a. Furthermore, a controller 19 that controls the operation of each device constituting the fuel cell system 1, a fuel cell 2, a hydrogen generator 3, a combustor 3 a, a raw material gas channel 5, a branch channel 10, and a fuel gas channel 12. , The exhaust gas passage 13, the bypass passage 14, the air blower 18 and the controller 19, the ventilation fan 21 as a ventilation means for ventilating the atmospheric gas in the housing, and the combustible gas concentration in the housing A combustible gas sensor 23 is provided as a combustible gas detection means for detection.

  Here, the controller 19 includes at least the source gas source valves 7a and 7b, the source gas supply valve 9, the source gas branch valve 11, the bypass valve 15, the anode inlet valve 16, the anode outlet valve 17, the air blower 18, and the ventilation fan. 21 is controlled.

  A series of specific operations related to leakage inspection and valve failure diagnosis of the fuel cell system 101 in the present embodiment will be described. FIG. 6 is a flow chart showing a series of operations for checking the sticking of the valve of the fuel cell system according to Embodiment 2 of the present invention, and FIG. 7 is a series of leak tests for the fuel cell system according to Embodiment 2 of the present invention. FIG. 8 is a flow chart showing the operation, FIG. 8 is a flow chart showing a series of operations for valve opening failure inspection of the fuel cell system in Embodiment 2 of the present invention, and FIG. It is a flowchart which shows a series of operation | movement of the leak inspection of a system.

  First, when a command for leakage inspection and valve failure diagnosis is output from the controller 19 while the fuel cell 2 and the hydrogen generator 3 are stopped, as shown in FIG. After closing the valve (step S401), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S402), and the gas is supplied to the source gas flow path 5 and the hydrogen generator 3. Here, when the pressure value P1 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S403), the raw material gas main valves 7a and 7b are closed (step). S404). Then, the bypass valve 15 is opened (step S405), the source gas flow path 5 and the hydrogen generator 3 are opened to the atmosphere, and the source gas flow rate F1 detected by the source gas flow meter 22 immediately after opening to the atmosphere is detected. (Step S406), it is determined whether or not the source gas flow rate F1 is greater than or equal to the second threshold value B (Step S407).

  When the raw material gas flow rate F1 is less than the second threshold B and the raw material gas flow rate is not recognized, it is determined that the raw material gas supply valve 9 or the bypass valve 15 is stuck abnormally, and the process proceeds to the next step S408. This is because, if the source gas supply valve 9 or the bypass valve 15 is not fixed, when the atmosphere is released by opening the bypass valve 15 in step S405, the source gas passes through the bypass channel and the exhaust gas channel. The flow rate value detected by the raw material gas flow meter should increase because it is opened, but it is estimated that either the raw material gas supply valve 9 or the bypass valve 15 is fixed. Because.

  When the source gas flow rate F1 is less than the second threshold B and the source gas flow rate is not recognized, in order to diagnose whether the fixed valve is the source gas supply valve 9 or the bypass valve 15, After all the valves are closed (step S408), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S409) to supply gas to the source gas flow path 5 and the hydrogen generator 3. Here, when the pressure value P2 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S410), the raw material gas main valves 7a and 7b are closed (step). S411). Then, the source gas branch valve 11 is opened (step S412), the source gas flow path 5 and the hydrogen generator 3 are opened to the atmosphere, and the source gas flow rate F2 detected by the source gas flow meter 22 immediately after being opened to the atmosphere is set. It is detected (step S413), and it is determined whether or not the source gas flow rate F2 is equal to or higher than the second threshold B (step S414).

  When the source gas flow rate F2 is equal to or higher than the second threshold B and the source gas flow rate is recognized, the source gas is opened to the atmosphere through the branch channel and the exhaust gas channel. It can be determined that the valve 11 is operating normally, and the fixed valve is abnormally stopped as the bypass valve 15 (step S415).

  If the source gas flow rate F2 is less than the second threshold B and the source gas flow rate is not recognized, it is estimated that the source gas supply valve 9 and the source gas branch valve 11 are fixed, and are fixed in step S407. Since the valve is estimated to be either the raw material gas supply valve 9 or the bypass valve 15, it can be assumed that the fixed valve is the raw material gas supply valve 9. The controller 19 stops abnormally as the material gas supply valve 9 is stuck abnormally (step S416).

  Next, in step S407, assuming that the raw material gas flow rate F1 is equal to or greater than the second threshold value B and there is no abnormal adhesion of the raw material gas supply valve 9 or the bypass valve 15, the adhesion inspection of the anode inlet valve 16 and the anode outlet valve 17 is performed. carry out. After all the valves are closed (step S417), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S418), and the gas is supplied to the source gas flow path 5 and the hydrogen generator 3. Here, when the pressure value P3 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S419), the raw material gas main valves 7a and 7b are closed (step). S420). Then, the anode inlet valve 16 and the anode outlet valve 17 are opened (step S421), the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12 and the fuel cell 2 are opened to the atmosphere. The pressure value F3 detected by the raw material gas flow meter 22 is detected (step S422), and it is determined whether or not it is equal to or greater than the third threshold value B (step S423).

  When the raw material gas flow rate F3 is less than the second threshold B and the raw material gas flow rate is not recognized, the anode inlet valve 16 or the anode outlet valve 17 is abnormally stopped as being abnormally stuck (step S424). This is because the material gas supply valve 9 is not fixed in step S407, and it can be assumed that the fixed valve is the anode inlet valve 16 or the anode outlet valve 17.

  Next, when the raw material gas flow rate F3 is equal to or higher than the third threshold value B and the raw material gas flow rate is recognized, it is assumed that the anode inlet valve 16 or the anode outlet valve 17 is not stuck abnormally, and the process proceeds to a leakage inspection.

  As described above, since the valve sticking abnormality is performed before the leak inspection, the gas can be reliably supplied to the hydrogen generator 3 and the fuel cell 2 at the time of the leak inspection, so that the detection error of the leakage abnormality can be reduced. Here, a series of operation flows regarding leakage inspection of the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12, and the fuel cell 2 will be described with reference to FIG.

  When the controller 19 shifts from the sticking inspection to the leak inspection, all the valves are first closed (step S501), and then the source gas source valves 7a and 7b, the source gas supply valve 9 and the anode inlet valve 16 are opened ( In step S502), gas is supplied to the raw material gas passage 5, the hydrogen generator 3, the fuel gas passage 12, and the fuel cell 2. Here, when the pressure value P1 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S503), the raw material gas flow rate detected by the raw material gas flow meter 22 is detected. F1 is detected (step S504), and it is determined whether the source gas flow rate F1 is less than the second threshold value B (step S505).

If the source gas flow rate F1 is equal to or higher than the second threshold B and the source gas flow rate is recognized (No in step S505), the flow path from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 leaks. As a result, the process proceeds to the next step S506. If the flow path from the source gas source valves 7a, 7b to the bypass valve 15 and the anode outlet valve 17 does not leak, the source gas source valve 7a is closed when the source gas source valves 7a, 7b are closed in step S504. , 7b should not be recognized as the raw material gas flow rate detected by the raw material gas flow meter 22, but the raw material gas flow rate is recognized as the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow. This is because any of the passage 12, the fuel cell 2, the bypass valve 15, and the anode outlet valve 17 is estimated to be leaking.

  Next, in order to specify the leak location, after closing all the valves (step S506), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S507), and the source gas channel 5 The gas is supplied to the hydrogen generator 3 and the fuel gas passage 12. Here, when the pressure value P2 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S508), the raw material gas flow rate detected by the raw material gas flow meter 22 is detected. F2 is detected (step S509), and it is determined whether the source gas flow rate F2 is less than the second threshold value B (step S510).

  If the source gas flow rate F2 is less than the second threshold B and the source gas flow rate is not recognized (Yes in step S510), the source material that is the branch flow path 10 from the source gas source valves 7a, 7b to the anode inlet valve 16 The gas flow path 5, the hydrogen generator 3, and the fuel gas flow path 12 are not leaking, and the fuel gas flow path 12, the fuel cell 2, and the exhaust gas flow path, which are flow paths from the anode inlet valve 16 to the anode outlet valve 17. In addition, it is determined that the anode outlet valve 17 is leaking, and abnormally stops as a leakage of the flow path from the anode inlet valve 16 to the anode outlet valve 17 (step S511).

  If the source gas flow rate F2 is equal to or higher than the second threshold B and the source gas flow rate is recognized (No in step S510), the flow path from the source gas source valves 7a, 7b to the bypass valve 15 and the anode outlet valve 17 leaks. As a result, the process proceeds to the next step S512. After all the valves are closed (step S512), the source gas source valves 7a and 7b are opened (step S513), and gas is supplied to the source gas flow path 5. Here, when the pressure value P3 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S514), the raw material gas flow rate detected by the raw material gas flow meter 22 is detected. F3 is detected (step S515), and it is determined whether the source gas flow rate F1 is less than the second threshold value B (step S516).

  When the source gas flow rate F3 is less than the second threshold B and the source gas flow rate is not recognized (Yes in step S516), the source gas that is the flow path from the source gas source valves 7a, 7b to the source gas supply valve 9 The flow path 5 is not leaking, and the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12, or the bypass flow path 14, which is a flow path from the raw material gas supply valve 9 to the bypass valve 15 and the anode inlet valve 16. Is determined to be leaking, and the flow is abnormally stopped as an abnormal leak in the flow path from the source gas supply valve 9 to the bypass valve 15 and the anode inlet valve 16 (step S517).

  When the source gas flow rate F3 is equal to or higher than the second threshold B and the source gas flow rate is recognized (No in step S516), the source gas flow that is a flow path from the source gas source valves 7a and 7b to the source gas supply valve 9 The passage 5 is determined to be leaking, and is abnormally stopped as a leakage abnormality of the flow path from the source gas source valves 7a, 7b to the source gas supply valve 9 (step S518).

  If the source gas flow rate F1 is less than the second threshold value B in step S505 and the source gas flow rate is not recognized (Yes in step S505), the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 are used. Assuming that the flow path is not leaking, the process proceeds to valve open failure inspection.

  Since the valve leakage abnormality is executed before the valve open failure inspection, the flow path from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 does not leak during the valve open failure inspection. Therefore, detection errors in the valve open failure inspection can be reduced. Here, a series of operation flows related to the open failure inspection for detecting whether or not the raw material gas supply valve 9 and the anode inlet valve 16 are closed in response to the closing command will be described with reference to FIG.

  When the controller 19 shifts from the leak test to the valve open failure test, first, after closing all the valves (step S601), the source gas source valves 7a and 7b and the bypass valve 15 are opened (step S602). Gas is supplied from the source gas source valves 7 a and 7 b to the source gas flow path 5 of the source gas supply valve 9. Here, when the pressure value P1 detected by the pressure detector 6 is equal to or higher than the first threshold A lower than the supply pressure of the raw material gas infrastructure (Yes in step S603), the raw material gas flow rate detected by the raw material gas flow meter 22 is detected. F1 is detected (step S604), and it is determined whether the source gas flow rate F1 is less than the second threshold value B (step S605).

  When the source gas flow rate F1 is equal to or higher than the second threshold B and the source gas flow rate is recognized (No in step S605), the source gas has passed through the source gas supply valve 9, and the source gas supply valve 9 has failed. As a result, the operation is abnormally stopped (step S606).

  If the source gas flow rate F1 is less than the second threshold B and the source gas flow rate is not recognized (Yes in step S605), the source gas does not pass through the source gas supply valve 9, and therefore the source gas supply valve 9 Is not an open failure, and the process proceeds to the next step S607. After the bypass valve 15 is closed (step S607), the source gas source valves 7a and 7b, the source gas supply valve 9 and the anode outlet valve 17 are opened (step S608), and the bypass gas 15 and the source gas source valves 7a and 7b are opened. Gas is supplied to the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12, and the bypass flow path 14 to the anode inlet valve 16. Here, when the pressure value P2 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S609), the raw material gas flow rate detected by the raw material gas flow meter 22 is detected. F2 is detected (step S610), and it is determined whether the source gas flow rate F2 is less than the second threshold value B (step S611).

  When the source gas flow rate F2 is equal to or higher than the second threshold B and the source gas flow rate is recognized (No in step S611), the source gas has passed through the anode inlet valve 16, and the anode inlet valve 16 has failed to open. It is abnormally stopped as being present (step S612).

  If the raw material gas flow rate F2 is less than the second threshold B and the raw material gas flow rate is not recognized (Yes in step S611), the anode inlet valve 16 is opened because the source gas has not passed through the anode inlet valve 16. There is no failure and the valve open adhesion test is terminated.

  In the leak inspection described based on FIG. 7, the combustible gas sensor 23 installed in the housing can be used without using the raw material gas flow meter 22. Here, with reference to FIG. 9, a series of operation flows regarding leakage inspection of the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12 and the fuel cell 2 when the combustible gas sensor 23 is used will be described. .

When the controller 19 shifts from the sticking test to the leak test, first, after closing all the valves (step S701), the source gas source valves 7a and 7b, the source gas supply valve 9 and the anode inlet valve 16 are opened ( In step S <b> 702, the gas is supplied to the source gas channel 5, the hydrogen generator 3, the fuel gas channel 12, and the fuel cell 2. Here, when the pressure value P1 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S703), the combustible gas concentration detected by the combustible gas sensor 23. D1 is detected (step S70).
4) It is determined whether or not the combustible gas concentration D1 is less than the second threshold value B (step S705).

  When the combustible gas concentration D1 is equal to or higher than the second threshold B and combustible gas is recognized in the casing (No in step S705), the flow from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 Assuming that the flow path is leaking, the process proceeds to the next step S706.

  Next, in order to specify the leak location, after closing all the valves (step S706), the source gas source valves 7a and 7b and the source gas supply valve 9 are opened (step S707), and the source gas flow path 5 The gas is supplied to the hydrogen generator 3 and the fuel gas passage 12. Here, when the pressure value P2 detected by the pressure detector 6 is equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S708), the combustible gas concentration detected by the combustible gas sensor 23. D2 is detected (step S709), and it is determined whether or not the combustible gas concentration D2 is less than the second threshold B (step S710).

  When the combustible gas concentration D2 is less than the second threshold B and no combustible gas is recognized in the housing (Yes in step S710), the branch flow path from the source gas source valves 7a, 7b to the anode inlet valve 16 10, the raw material gas flow path 5, the hydrogen generator 3 and the fuel gas flow path 12 are not leaking, and the fuel gas flow path 12, which is a flow path from the anode inlet valve 16 to the anode outlet valve 17, the fuel cell 2, and It is determined that the exhaust gas flow path and the anode outlet valve 17 are leaking, and the flow is abnormally stopped as an abnormal leakage of the flow path from the anode inlet valve 16 to the anode outlet valve 17 (step S711).

  When the flammable gas concentration D2 is equal to or higher than the second threshold B and flammable gas is recognized in the casing (No in step S710), from the source gas source valves 7a and 7b to the bypass valve 15 and the anode outlet valve 17 The flow proceeds to the next step S712. After all the valves are closed (step S713), the source gas source valves 7a and 7b are opened (step S714), and gas is supplied to the source gas channel 5. Here, when the pressure value P3 detected by the pressure detector 6 becomes equal to or higher than the first threshold value A lower than the supply pressure of the raw material gas infrastructure (Yes in step S714), the combustible gas concentration detected by the combustible gas sensor 23. D3 is detected (step S715), and it is determined whether or not the combustible gas concentration D3 is less than the second threshold B (step S716).

  When the combustible gas concentration D3 is less than the second threshold B and no combustible gas is recognized in the housing (Yes in step S716), the flow path from the source gas source valves 7a, 7b to the source gas supply valve 9 The raw material gas flow path 5 is not leaking, and the raw material gas flow path 5, the hydrogen generator 3, the fuel gas flow path 12 or the flow path from the raw material gas supply valve 9 to the bypass valve 15 and the anode inlet valve 16 It is determined that the bypass flow path 14 is leaking, and the flow is abnormally stopped as a flow path leak from the source gas supply valve 9 to the bypass valve 15 and the anode inlet valve 16 (step S717).

  When the combustible gas concentration D3 is less than the second threshold B and no combustible gas is recognized in the casing (No in step S716), the flow path from the source gas source valves 7a, 7b to the source gas supply valve 9 It is determined that the raw material gas flow path 5 is leaking, and abnormally stops as a flow path leakage abnormality from the raw material gas main valves 7a, 7b to the raw material gas supply valve 9 (step S717).

  When the combustible gas concentration D1 is less than the second threshold value B in step S705 and no combustible gas is recognized in the housing (Yes in step S705), the raw material gas main valves 7a and 7b to the bypass valve 15 and the anode outlet are used. Assuming that the flow path to the valve 17 is not leaking, the process proceeds to the valve open failure inspection.

  The fuel cell system of the present invention is useful for, for example, a fuel cell system used for a cogeneration apparatus.

DESCRIPTION OF SYMBOLS 1 Fuel cell system 2 Fuel cell 3 Hydrogen generator 3a Combustor 4 Raw material gas infrastructure 5 Raw material gas flow path 6 Pressure detector 7a, 7b Raw material gas main valve 8 Raw material supply means 9 Raw material gas supply valve 10 Branch flow path 11 Raw material gas Branch valve 12 Fuel gas flow path 13 Exhaust gas flow path 14 Bypass flow path 15 Bypass valve 16 Anode inlet valve 17 Anode outlet valve 18 Air blower 19 Controller 20 Housing 21 Ventilation fan 22 Raw material gas flow meter 23 Flammable gas sensor

Claims (9)

A hydrogen generator for generating a fuel gas containing hydrogen from a raw material gas and water vapor by a reforming reaction;
A fuel cell that generates electric power using the fuel gas containing hydrogen and an oxidant gas containing oxygen;
A source gas flow path supplied to the hydrogen generator and connected to the source gas infrastructure;
A pressure detector for detecting the pressure in the source gas flow path;
A first valve disposed upstream of the pressure detector in the source gas flow path;
A second valve disposed upstream of the hydrogen generator and downstream of the pressure detector in the source gas flow path, and a branch branched from between the second valve and the hydrogen generator in the source gas flow path A flow path;
A third valve disposed on the branch flow path;
A fuel gas flow path for introducing the fuel gas generated by the hydrogen generator into the fuel cell;
An exhaust gas passage for discharging the fuel gas from the fuel cell to the atmosphere;
A bypass passage that bypasses the fuel cell and connects the fuel gas passage and the exhaust gas passage;
A fourth valve disposed on the bypass flow path;
A fifth valve disposed on the fuel gas flow path between the fuel cell and a branch point with the bypass flow path on the fuel gas flow path;
A sixth valve disposed on the exhaust gas flow path between the joining points of the exhaust gas flow path and the bypass flow path from the fuel cell;
A fuel cell system comprising a controller,
As the sticking inspection, the controller detects whether the second valve and the fourth valve are opened in response to an opening command in a state where the operation of the hydrogen generator and the fuel cell is stopped. ,
(1) After closing the sixth valve from the first valve, opening the first valve and the second valve, supplying the source gas, and then closing the first valve, the pressure detector Detecting the first pressure by
(2) When the second pressure is detected by the pressure detector after the fourth valve is opened, and the first pressure and the second pressure are not equal, the second valve and the fourth valve The valve is judged normal and
(3) When the first pressure and the second pressure are equal, the second valve and the fourth valve are determined to be abnormal,
(4) After closing the sixth valve from the first valve, opening the first valve and the second valve, supplying the raw material gas, and then closing the first valve, the pressure detector Detecting the third pressure by
(5) When the fourth pressure is detected by the pressure detector after the third valve is opened and the third pressure and the fourth pressure are not equal, the fourth valve is determined to be abnormal. And
(6) The fuel cell system, wherein when the third pressure and the fourth pressure are equal, the second valve is determined to be abnormal. The raw material gas flow path includes a raw material supply amount detection means for detecting the supply amount of the raw material gas,
As the sticking inspection, the controller detects whether the second valve and the fourth valve are opened in response to an opening command in a state where the operation of the hydrogen generator and the fuel cell is stopped. ,
(1) After closing the sixth valve from the first valve, the first valve and the second valve are opened to supply the source gas, the first valve is closed, and the fourth valve is further closed. When the first raw material supply amount is detected by the raw material supply amount detection means immediately after opening, and the first raw material supply amount is larger than a specified value, it is determined that the second valve and the fourth valve are normal. ,
(2) When the first raw material supply amount is less than a specified value, the second valve and the fourth valve are determined to be abnormal,
(3) After closing the sixth valve from the first valve, opening the first valve and the second valve and supplying the raw material gas, then closing the first valve, and further Detecting the second raw material supply amount by the raw material supply means after opening the valve, and determining that the fourth valve is abnormal when the second raw material supply amount is less than a specified value;
(4) The fuel cell system according to claim 1, wherein when the second raw material supply amount is greater than a specified value, the second valve is determined to be abnormal. The controller, after the sticking inspection is executed, in a state in which the hydrogen generator and the fuel cell are stopped, leakage inspection of a flow path from the first valve to the fourth valve and the sixth valve As
(1) The first to sixth valves are closed, the first valve, the second valve, and the fifth valve are opened, the source gas is supplied, and then the first valve is closed. Detecting a first pressure by the pressure detector immediately after the first valve is closed,
(2) When the second pressure is detected by the pressure detector after a predetermined time has elapsed since the first valve was closed, and the first pressure and the second pressure are equal, It is determined that the flow path from the first valve to the fourth valve and the fifth valve is normal,
(3) When the first pressure and the second pressure are not equal, the first to sixth valves are closed, the first valve and the second valve are opened, and the source gas is supplied. After supply, close the first valve, detect the third pressure by the pressure detector immediately after the first valve closed,
(4) When the fourth pressure is detected by the pressure detector after a lapse of a predetermined time after the first valve is closed, and the third pressure and the fourth pressure are equal, It is determined that the flow path from the fifth valve to the sixth valve is abnormal,
(5) When the third pressure and the fourth pressure are not equal, the first to sixth valves are closed, the first valve and the fourth valve are opened, and the source gas is supplied. After supply, close the first valve, detect the fifth pressure by the pressure detector immediately after the first valve closed,
(6) When the sixth pressure is detected by the pressure detector after a predetermined time has elapsed since the first valve was closed, and the fifth pressure and the sixth pressure are equal, It is determined that the flow path from the second valve to the fourth valve and the fifth valve is abnormal,
(7) The fuel cell system according to claim 1 or 2, wherein when the fifth pressure and the sixth pressure are not equal, the flow path from the first valve to the second valve is determined to be abnormal. . The controller, after the sticking inspection is executed, in a state in which the hydrogen generator and the fuel cell are stopped, leakage inspection of a flow path from the first valve to the fourth valve and the sixth valve As
(1) After the first to sixth valves are closed, the first valve, the second valve, and the fifth valve are opened and the raw material gas is supplied, the raw material supply amount detecting means When the first raw material supply amount is detected and the first raw material supply amount is less than a specified value, it is determined that the flow paths from the first valve to the fourth valve and the fifth valve are normal,
(2) When the first raw material supply amount is larger than a specified value, the first to sixth valves are closed, the first valve and the second valve are opened, and the raw material gas is supplied. When the second raw material supply amount is detected by the raw material supply amount detection means and the second raw material supply amount is less than a specified value, it is determined that the flow path from the fifth valve to the sixth valve is abnormal,
(3) When the second raw material supply amount is larger than a specified value, the first to sixth valves are closed, the first valve and the fourth valve are opened, and the raw material gas is supplied. When the third raw material supply amount is detected by the raw material supply amount detection means and the third raw material supply amount is less than a specified value, the flow paths of the fourth valve to the fourth valve and the fifth valve are abnormal. Judging
(4) The fuel cell system according to claim 1 or 2, wherein when the third raw material supply amount is larger than a specified value, the flow path from the first valve to the second valve is determined to be abnormal. A housing that houses at least the hydrogen generator, the fuel cell, and the controller;
Comprising flammable gas detection means for detecting flammable gas in the housing;
The controller, after the sticking inspection is executed, in a state in which the hydrogen generator and the fuel cell are stopped, leakage inspection of a flow path from the first valve to the fourth valve and the sixth valve As
(1) After the first to sixth valves are closed, the first valve, the second valve, and the fifth valve are opened and the raw material gas is supplied, the combustible gas detection means When the first combustible gas concentration is detected and the first combustible gas concentration is lower than a specified value, the flow paths from the first valve to the fourth valve and the fifth valve are determined to be normal,
(2) After the first combustible gas concentration is higher than a specified value, the first to sixth valves are closed, the first valve and the second valve are opened, and the source gas is supplied. The second combustible gas concentration is detected by the combustible gas detection means, and when the second combustible gas concentration is lower than a specified value, it is determined that the flow path from the fifth valve to the sixth valve is abnormal. And
(3) When the concentration of the second combustible gas is higher than a specified value, the first to sixth valves are closed, the first valve and the fourth valve are opened, and the source gas is supplied. When the third combustible gas concentration is detected by the combustible gas detection means and the third combustible gas concentration is lower than a specified value, the flow from the second valve to the fourth valve and the fifth valve Judging that the road is abnormal,
(4) The fuel cell system according to claim 1 or 2, wherein when the third combustible gas concentration is higher than a specified value, the flow path from the first valve to the second valve is determined to be abnormal. The controller determines whether or not the second valve and the fifth valve are closed with respect to a closing command in a state where the hydrogen generator and the fuel cell are stopped after the leakage inspection is performed. As an open fault inspection to detect
(1) The first to sixth valves are closed, the first valve and the fourth valve are opened to supply the raw material gas, the first valve is closed, and the first valve is closed. Detecting the first pressure by the pressure detector immediately after,
(2) When the second pressure is detected by the pressure detector after a predetermined time has passed since the first valve was closed, and the first pressure and the second pressure are not equal, the second pressure The valve is determined to be abnormal, and (3) when the first pressure and the second pressure are equal,
After closing the fourth valve, opening the first valve, the second valve, and the sixth valve and supplying the raw material gas, the first valve is closed, and the first valve is closed immediately after the first valve is closed. Detect the third pressure by the pressure detector,
(4) When the fourth pressure is detected by the pressure detector after a lapse of a predetermined time after the first valve is closed, and the third pressure and the fourth pressure are not equal, 6. The valve according to claim 3, wherein the valve is determined to be abnormal, and (5) the fourth valve is determined to be normal when the third pressure and the fourth pressure are not equal. Fuel cell system. The controller determines whether or not the second valve and the fifth valve are closed with respect to a closing command in a state where the hydrogen generator and the fuel cell are stopped after the leakage inspection is performed. As an open fault inspection to detect
(1) After the first to sixth valves are closed, the first valve and the fourth valve are opened and the raw material gas is supplied, the first raw material supply amount by the raw material supply amount detection means When the first raw material supply amount is greater than a specified value, the second valve is determined to be abnormal,
(2) After the first raw material supply amount is lower than a specified value, the fourth valve is closed, the first valve, the second valve and the sixth valve are opened and the raw material gas is supplied. Detecting the second raw material supply amount by the raw material supply amount detection means, and determining that the fourth valve is abnormal when the second raw material supply amount is greater than a specified value;
(3) The fuel cell system according to any one of claims 1 to 5, wherein when the second raw material supply amount is less than a specified value, the fourth valve is determined to be normal. A housing that houses at least the hydrogen generator, the fuel cell, and the controller;
Ventilation means for venting the atmospheric gas in the housing,
3. The fuel cell system according to claim 1, wherein the controller operates the ventilation unit when executing at least one of the sticking test, the leak test, and the open fault test. A combustor for heating the hydrogen generator;
Air supply means for supplying combustion air to the combustor;
The exhaust gas flow path is led to the combustor;
3. The fuel cell system according to claim 1, wherein the controller operates the air supply unit when executing at least one of the sticking test, the leak test, and the open fault test.

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