JP4984124B2 - Fuel cell system and vehicle equipped with the same - Google Patents

Description

  The present invention relates to a fuel cell system equipped with a fuel cell that is supplied with a reaction gas and generates power by an electrochemical reaction, and a vehicle equipped with the fuel cell system.

In recent years, a fuel cell vehicle using a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidizing gas as an energy source has attracted attention. As a fuel cell system mounted on this fuel cell vehicle or the like, the pressure in the tank that stores the fuel gas at a pressure higher than the normal pressure is detected by a pressure sensor, and the fuel gas in the tank is detected based on the detection result. There is known one that obtains and displays the remaining amount (see, for example, Patent Document 1).
JP-A-2005-240854

  By the way, in this type of fuel cell system, water is generated by an electrochemical reaction during power generation. However, in a low temperature environment, the generated water freezes in the gas flow path and causes a decrease in power generation efficiency. At the time of stoppage, a low-temperature response process for purging the generated water remaining in the gas flow path is performed by feeding the fuel gas and the oxidizing gas. Therefore, the fuel gas consumption varies depending on the presence or absence of this low-temperature treatment, and the fuel gas remaining amount display in the tank becomes inaccurate.

  The present invention has been made in view of such circumstances, and is equipped with a fuel cell system capable of accurately grasping the remaining amount of reaction gas in the gas supply source regardless of the presence or absence of low-temperature processing. An object is to provide a vehicle.

  In order to achieve the above object, a fuel cell system according to the present invention includes a gas supply source that stores a reaction gas at a pressure higher than normal pressure, and a fuel that generates power through an electrochemical reaction when the reaction gas is supplied from the gas supply source. A battery, a display device that displays a remaining amount of the reaction gas in the gas supply source, and a remaining amount of the reaction gas obtained based on a pressure in the gas supply source; A control unit for displaying, and the control unit adjusts the display on the display device in accordance with the presence or absence of a low-temperature handling process performed when the system is stopped.

  Examples of the low-temperature treatment process include a purge process for purging a reaction gas flow path including at least the inside of the fuel cell with the reaction gas.

  According to the fuel cell system having this configuration, the control unit adjusts the display on the display device according to the presence or absence of low temperature (for example, below freezing point) processing such as purging the reaction gas channel with the reaction gas. Even if the consumption amount of the reaction gas is increased by performing the low temperature response process at the time of stopping, the remaining amount of the reaction gas can be displayed with high accuracy on the display device together with the case where the low temperature response process is not performed.

  In the fuel cell system of the present invention, the display device may include a warning light, and the control unit may change the lighting timing of the warning light according to the presence or absence of the low-temperature handling process.

  In addition, according to the vehicle of the present invention equipped with the fuel cell system described above, it is possible to accurately grasp the power generation possible time and the travelable distance of the fuel cell regardless of the presence or absence of low-temperature processing such as purge processing. .

  According to the present invention, the remaining amount of the reaction gas in the gas supply source can be grasped with high accuracy regardless of the presence or absence of the low temperature treatment.

  First, the overall configuration of a fuel cell system according to an embodiment of the present invention will be described. This fuel cell system is an in-vehicle power generation system for a fuel cell vehicle. In addition to a fuel cell system mounted on a vehicle, a fuel cell system for any moving body such as a ship, an aircraft, a train, a walking robot, or the like, for example, a fuel cell However, it can also be applied to stationary fuel cell systems used as power generation equipment for buildings (housing, buildings, etc.).

  As shown in FIG. 1, the air as the oxidizing gas (reactive gas) is supplied to the air supply port of the fuel cell 20 via the air supply path 71. The air supply path 71 is provided with an air cleaner A1 that removes and cleans particles from the air, a compressor A3 that pressurizes the air, a pressure sensor P4 that detects the supply air pressure, and a humidifier A21 that adds required moisture to the air. Yes. The compressor A3 is driven by a motor. This motor is driven and controlled by the control unit 50.

  The air off gas discharged from the fuel cell 20 is discharged to the outside through the exhaust path 72. The exhaust path 72 is provided with a pressure sensor P1 that detects the exhaust pressure, a pressure adjustment valve A4, and a heat exchanger for the humidifier A21. The pressure sensor P <b> 1 is provided in the vicinity of the air exhaust port of the fuel cell 20. The pressure adjustment valve A4 functions as a pressure regulator that sets the supply air pressure to the fuel cell 20.

  Detection signals from the pressure sensors P4 and P1 are sent to the control unit 50. The control unit 50 sets the supply air pressure and the supply air flow rate to the fuel cell 20 by adjusting the motor rotation speed of the compressor A3 and the opening area of the pressure adjustment valve A4.

  Hydrogen gas as a fuel gas (reactive gas) is supplied from the hydrogen supply source 30 to the hydrogen supply port of the fuel cell 20 via the fuel supply path 74. The fuel supply path 74 includes a shutoff valve H100 that supplies or stops supplying hydrogen from the hydrogen supply source 30, a pressure sensor P6 that detects the supply pressure of hydrogen gas from the hydrogen supply source 30, and hydrogen gas to the fuel cell 20. The pressure regulating valve H9 for reducing and adjusting the supply pressure of the fuel, the pressure sensor P9 for detecting the hydrogen gas pressure downstream of the hydrogen pressure regulating valve H9, and the shutoff valve H21 for opening and closing between the hydrogen supply port of the fuel cell 20 and the fuel supply path 74. , And a pressure sensor P5 for detecting the inlet pressure of the hydrogen gas fuel cell 20 is provided. Detection signals from these pressure sensors P5, P6, and P9 are also supplied to the control unit 50.

  The hydrogen gas that has not been consumed in the fuel cell 20 is discharged to the hydrogen circulation path 75 as a hydrogen off-gas and returned to the downstream side of the hydrogen pressure regulating valve H9 in the fuel supply path 74. The hydrogen circulation path 75 includes a temperature sensor T31 that detects the temperature of the hydrogen off-gas, a shutoff valve H22 that communicates / blocks the fuel cell 20 and the hydrogen circulation path 75, and a gas-liquid separator H42 that collects moisture from the hydrogen off-gas. A drain valve H41 that collects the produced water in a tank (not shown) outside the hydrogen circulation path 75 and a hydrogen pump H50 that pressurizes the hydrogen off-gas are provided.

  The shutoff valves H21 and H22 close the anode side of the fuel cell 20. A detection signal (not shown) of the temperature sensor T31 is supplied to the control unit 50. The operation of the hydrogen pump H50 is controlled by the control unit 50. The hydrogen off gas merges with the hydrogen gas in the fuel supply path 74 and is supplied to the fuel cell 20 for reuse. The shutoff valves H100, H21, and H22 are driven by a signal from the control unit 50.

  The hydrogen circulation path 75 is connected to the exhaust path 72 by the purge flow path 76 via the discharge control valve H51. The discharge control valve H51 is an electromagnetic shut-off valve, and discharges (purges) hydrogen off-gas to the outside by operating according to a command from the control unit 50. By performing this purge operation intermittently, it is possible to prevent the cell voltage from decreasing due to repeated hydrogen off-gas circulation and increasing the impurity concentration of the hydrogen gas on the fuel electrode side.

  A cooling path 73 for circulating the cooling water is provided at the cooling water inlet / outlet of the fuel cell 20. In the cooling path 73, a temperature sensor T1 that detects the temperature of the cooling water drained from the fuel cell 20, a radiator (heat exchanger) C2 that radiates the heat of the cooling water to the outside, and a pump that pressurizes and circulates the cooling water. C1 and a temperature sensor T2 for detecting the temperature of the cooling water supplied to the fuel cell 20 are provided. The radiator C2 is provided with a cooling fan C13 that is rotationally driven by a motor.

  The fuel cell 20 is configured as a fuel cell stack in which a required number of single cells that receive supply of fuel gas and oxidant gas and generate electric power through an electrochemical reaction are stacked. The electric power generated by the fuel cell 20 is supplied to a power control unit (not shown). The power control unit consists of an inverter that supplies electric power to the drive motor of the vehicle, an inverter that supplies electric power to various auxiliary devices such as a compressor motor and a motor for a hydrogen pump, and charging of power storage means such as a secondary battery. A DC-DC converter or the like that supplies power to the motors from the power storage means is provided.

  The control unit 50 receives control information from a requested load such as an accelerator signal of a vehicle (not shown) and sensors (pressure sensor, temperature sensor, flow rate sensor, output ammeter, output voltmeter, etc.) of each part of the fuel cell system 1, Control the operation of valves and motors in each part.

  The fuel cell system 1 is provided with a warning light (display device) 51, and the warning light 51 is turned on / off based on a signal from the control unit 50. The warning light 51 is installed in a place that can be visually recognized by a vehicle occupant, and the control unit 50 calculates the remaining amount of hydrogen gas in the hydrogen supply source 30, and the calculated remaining amount is equal to a predetermined threshold value. At that time, the warning light 51 is turned on.

  Here, in the fuel cell system 1, water is generated by an electrochemical reaction during power generation. For example, in a low-temperature environment where the outside air temperature is below freezing point, the generated water is frozen in the gas flow path and the power generation efficiency is improved. Incurs a decline. For this reason, the fuel cell system 1 can perform low-temperature treatment processing for purging the generated water remaining in the gas flow path by sending hydrogen gas and air when the system 1 is stopped in the low-temperature environment. ing.

  That is, the fuel cell system 1 can be switched to a low temperature compatible processing mode in which low temperature compatible processing is performed or a non-low temperature compatible processing mode in which this low temperature compatible processing is not performed.

  In addition, as a switching means between the low-temperature compatible processing mode and the non-low-temperature compatible processing mode, for example, there is a switching by ON / OFF of a low temperature switch operated by a passenger. In this case, when the occupant turns on the low temperature switch, the fuel cell system 1 enters the low temperature processing mode.

  In addition, the mode switching means includes switching based on position information from GPS, switching based on date / time information, switching based on weather forecast information, and switching based on the measurement result of the outside temperature.

  Here, in the switching means based on the position information from the GPS, the low temperature processing mode is set when the use area of the vehicle is a cold region based on the position information, and in the winter when the outside temperature is low in the switching means based on the date / time information. If the temperature is predicted to be low from the temperature forecast, the low temperature processing mode will be used when switching from the weather forecast information. In the means, the temperature outside the vehicle is directly measured, and when the temperature is low, the low temperature processing mode is set.

  By the way, in this low-temperature treatment mode, hydrogen gas is consumed for the purge process, so that the rate of reduction of hydrogen gas is higher than in the non-low-temperature treatment mode in which the purge process is not performed. For this reason, the amount of hydrogen gas consumed varies depending on the presence or absence of low-temperature processing, that is, whether or not purge processing is performed, and the remaining amount of hydrogen gas in the hydrogen supply source 30 at the time of system startup becomes inaccurate. .

  Therefore, the control unit 50 controls the lighting / extinguishing of the warning lamp 51 at the time of starting the system in accordance with the switching between the low temperature processing mode or the non-low temperature processing mode as follows.

  FIG. 2 is a flowchart illustrating the lighting control of the warning lamp. First, the control unit 50 determines whether the fuel cell system 1 is in the low temperature compatible processing mode or the non-low temperature compatible processing mode (step S01).

  When the control unit 50 determines that the fuel cell system 1 is in the non-low temperature compatible processing mode in which the purging process is not performed, the control unit 50 determines the hydrogen gas in the hydrogen supply source 30 based on the detection result from the pressure sensor P6. When the remaining amount is calculated and it is determined that the remaining amount has reached the first remaining amount (first threshold) calculated from the consumption of hydrogen gas in the fuel cell 20 during normal operation (step S02). Then, a signal is transmitted to the warning lamp 51, and the warning lamp 51 is turned on (step S03).

  On the other hand, when the control unit 50 determines that the fuel cell system 1 is in the low temperature compatible processing mode in which the purge process is performed, the hydrogen in the hydrogen supply source 30 calculated based on the detection result from the pressure sensor P6. The remaining amount of gas is a second remaining amount (second threshold value) calculated from both the consumption amount of hydrogen gas in the fuel cell 20 during normal operation and the consumption amount of hydrogen gas in the purge process when the system is stopped. ) (Step S04), a signal is transmitted to the warning lamp 51, and the warning lamp 51 is turned on (step S03).

  Thus, according to the fuel cell system 1 according to the embodiment and the vehicle equipped with the fuel cell system 1, the control unit 50 determines the display timing in the warning lamp 51 according to the presence or absence of the purge process that is one form of the low-temperature handling process. Is adjusted (changed), so that the remaining amount of fuel gas can be displayed with high accuracy by the warning lamp 51 regardless of whether or not the purge process is performed when the system is stopped.

  Thus, the vehicle occupant can accurately grasp the travelable distance of the vehicle from the warning light 51 in either the low-temperature response processing mode or the non-low-temperature response processing mode.

  The power generation time of the fuel cell 20 or the travelable distance of the vehicle is obtained directly from the detection result of the pressure sensor P6 or from the remaining amount of hydrogen gas in the hydrogen supply source 30 calculated from the detection result, and these power generations are possible. The warning lamp 51 may be turned on when the time or the travelable distance reaches a predetermined threshold.

  In the above embodiment, the remaining amount of hydrogen gas is indicated by the warning lamp 51. However, the remaining power generation time or the distance that can be traveled may be indicated by a fuel gauge. Regardless, it is possible to easily and accurately grasp the power generation possible time in the fuel cell 20 or the vehicle travelable time by the indicator of the fuel gauge.

  Further, in the above embodiment, the flow rate of hydrogen gas from the hydrogen supply source 30 is adjusted by the hydrogen pressure regulating valve H9 and supplied to the fuel cell 20. However, instead of the hydrogen pressure regulating valve H9, the valve is directly opened and closed by electromagnetic driving force. A drive injector may be provided, and a gas flow rate required by the injector may be supplied to the fuel cell 20.

1 is a system configuration diagram schematically showing a fuel cell system according to an embodiment of the present invention. It is a flowchart explaining lighting control of a warning lamp.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 20 ... Fuel cell, 30 ... Hydrogen supply source (gas supply source), 50 ... Control part, 51 ... Warning lamp (display apparatus).

Claims (4)

A gas supply source for storing the reaction gas at a pressure higher than normal pressure;
A fuel cell that is supplied with a reactive gas from the gas supply source and generates power by an electrochemical reaction;
A display device for displaying the remaining amount of reaction gas in the gas supply source;
A controller that obtains the remaining amount of the reaction gas based on the pressure in the gas supply source, and displays the remaining amount of the reaction gas on the display device,
The said control part is a fuel cell system which adjusts the display in the said display apparatus according to the presence or absence of the low temperature response process implemented at the time of a system stop.   2. The fuel cell system according to claim 1, wherein the low-temperature handling process is a purge process for purging a reaction gas flow path including at least the inside of the fuel cell with the reaction gas. The display device comprises a warning light,
The fuel cell system according to claim 1 or 2, wherein the control unit changes a lighting timing of the warning lamp according to whether or not the low-temperature handling process is performed.   A vehicle comprising the fuel cell system according to any one of claims 1 to 3.

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