JP-7856039-B2 - Fuel cell system
Inventors
- 奥村 真己人
- 難波 良一
Assignees
- トヨタ自動車株式会社
Dates
- Publication Date
- 20260511
- Application Date
- 20230411
Claims (3)
- The system comprises a pressure sensor provided in an anode gas circulation path that circulates anode off-gas discharged from the fuel cell stack back to the fuel cell stack, a first valve that opens and closes an exhaust path branching off from the anode gas circulation path, a second valve connected to a gas-liquid separator provided in the anode gas circulation path and, when open, discharges gas and liquid from the gas-liquid separator to an exhaust drainage path, and a control device that determines abnormalities in the opening and closing of the first and second valves. The fuel cell system is characterized in that the control device determines an abnormal opening or closing of the first valve or the second valve based on a comparison between a first pressure decrease rate, which is the rate at which the pressure detected by the pressure sensor decreases when a first control is performed to open the first valve while the second valve is closed, and a second pressure decrease rate, which is the rate at which the pressure detected by the pressure sensor decreases when a second control is performed to open the second valve while the first valve is closed.
- The control device is When the first pressure drop rate is lower than the second pressure drop rate, a first valve closure abnormality that impedes the opening operation of the first valve is determined. The fuel cell system according to claim 1, characterized in that when the second pressure drop rate is lower than the first pressure drop rate, a second valve closure abnormality that impedes the opening operation of the second valve is determined.
- The control device is When the third control is performed to close both the first valve and the second valve, it is determined whether the third pressure decrease rate, which is the rate at which the pressure detected by the pressure sensor decreases, satisfies a leak condition where the pressure decreases above a predetermined value. When the aforementioned leak condition is met and the second pressure drop rate is higher than the first pressure drop rate, a first valve opening abnormality that impedes the closing operation of the first valve is determined. The fuel cell system according to claim 1, characterized in that when the leak condition is met and the first pressure drop rate is higher than the second pressure drop rate, a second valve opening abnormality that impedes the closing operation of the second valve is determined.
Description
This disclosure relates to fuel cell systems. Fuel cell systems have been known for some time. The fuel cell system described in Patent Document 1 below comprises a fuel cell, an anode gas supply system, an anode gas circulation system, a cathode gas supply and discharge system, an exhaust and drainage channel, an exhaust and drainage valve for opening and closing the exhaust and drainage channel, a flow rate acquisition unit, and a control unit. In the fuel cell system described in Patent Document 1, the control unit, while issuing an opening instruction to the exhaust and drain valve, performs a normal or abnormal valve opening determination as follows: The control unit determines that the exhaust and drain valve is normally open if the anode gas exhaust flow rate is equal to or greater than a predetermined normal standard value, and determines that the exhaust and drain valve is not normally open if the exhaust flow rate is lower than the normal standard value. Furthermore, the fuel cell system described in Patent Document 2 below comprises a fuel cell, an oxidant gas supply pipe through which oxidant gas flows to the fuel cell, and an oxidant off-gas discharge pipe through which oxidant off-gas from the fuel cell flows. This conventional fuel cell system also includes a pressure regulating valve provided in the oxidant off-gas discharge pipe to adjust the pressure of the oxidant gas within the fuel cell, a gas-liquid separator provided in the oxidant off-gas discharge pipe to separate liquid water from the oxidant off-gas, and an exhaust drain valve that serves both as an exhaust drain valve and an exhaust drain valve for the liquid reservoir of the gas-liquid separator. Furthermore, the fuel cell system described in Patent Document 2 includes a pressure sensor for measuring the pressure of the oxidizer gas in the fuel cell, and an ECU (Electrical Control Unit). The ECU controls the pressure regulating valve to a predetermined opening degree so that the pressure of the oxidizer gas in the fuel cell reaches a target pressure. Subsequently, the ECU performs pressure control, adjusting the opening degree of the pressure regulating valve so that the pressure based on the measurement value measured by the pressure sensor reaches the target pressure. If the adjustment range of the opening degree of the pressure regulating valve during pressure control is greater than a predetermined value, it determines that there is an abnormality in the opening and closing of the exhaust drain valve. Japanese Patent Publication No. 2020-017435Japanese Patent Publication No. 2022-132887 A process flow diagram showing one embodiment of the fuel cell system relating to this disclosure.A flowchart showing the processing of the control device for the fuel cell system in Figure 1.Figure 2 is a time chart showing the pressure detection values and the open/closed state of each valve during each process.A flowchart showing another process of the control device for the fuel cell system in Figure 1.Figure 4 is a time chart showing the pressure detection values and the open/closed state of each valve during each process. The embodiments of the fuel cell system according to this disclosure will be described below with reference to the drawings. Figure 1 is a process flow diagram showing one embodiment of the fuel cell system according to this disclosure. The fuel cell system 100 of this embodiment is mounted on a vehicle, such as a fuel cell vehicle, and supplies power to an on-board device, including an electric motor for driving. The fuel cell system 100 of this embodiment includes, for example, a fuel cell stack 110, an anode gas supply system 120, a cathode gas supply system 130, an anode gas circulation system 140, and a gas-liquid discharge system 150. The fuel cell system 100 also includes, for example, a cooling water circulation system (not shown) and a control device. The fuel cell stack 110 has a configuration in which, for example, multiple solid oxide fuel cell single cells are stacked, and has an anode gas inlet 111, an anode off-gas outlet 112, a cathode gas inlet 113, and a cathode off-gas outlet 114. The fuel cell stack 110 also has, for example, a cooling water inlet and a cooling water outlet (not shown in the figure). The anode gas supply system 120 includes, for example, an anode gas supply passage 121 connected to a high-pressure tank (not shown) via a pressure reducing valve, and an injector 122, supplying hydrogen gas as anode gas to the fuel cell stack 110. The control device of the fuel cell system 100 can, for example, control the pressure of the low-pressure anode gas flowing downstream of the injector 122 by controlling the injector 122. The cathode gas supply system 130 includes, for example, a cathode gas supply passage 131 connected to an air cleaner (not shown), a compressor 132, an intercooler 133, a flow divider valve 134, a sealing valve 135, and a pressure regulating valve 136. The cathode gas supply