JP2001143735A - Fuel cell system for vehicles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance efficiency of a fuel cell for vehicles. SOLUTION: A fuel cell system 100 for vehicles comprises two rows of fuel cells 110, 120, a fuel hydrogen tank 130, and compressors 150, 160 supplying air into each of the fuel cell. A control unit 180 detects the output of the fuel cell and controls compression motors 152, 154 and the opening degree of valves 141, 142 for controlling the quantity of flow of hydrogen. A driving unit 170 accepts the output from the fuel cell to drive a driving motor 172, etc. When the required output is less than 20% of a maximum output of the fuel cell, the control unit 180 stops operation of one row of the fuel cell and raises two times an output of the other row of the fuel cell to operate the fuel cell in the high region of operation efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fuel cell system for a vehicle.

[0002]

2. Description of the Related Art A fuel cell system is disclosed in, for example,
No. 211336 discloses a stack in which a hydrogen fuel obtained by reforming a raw fuel such as a natural gas, and a hydrogen electrode and an oxygen electrode, which are provided with an electrolyte layer interposed therebetween, are stacked via a separator. To generate electricity.

FIG. 3 shows a configuration of a fuel cell system for a vehicle, for example, and a first line L1 in which a charger 10 for supplying air and four stacks 11, 12, 13, and 14 are connected in series. And the charging machine 20 and the four stacks 21,
It has a second line L2 in which 22, 23 and 24 are connected in series.

[0004] The stack of the first line uses, for example, hydrogen as fuel, and has an ability to generate 25 KW per stack. The output of this stack is determined by the pressure and the air flow rate of the air supplied by the feeder, and a maximum output of 100 KW of peak power W1 can be obtained from the four stacks. The second line L2 also has the same configuration, and can obtain a peak output W2 of a maximum of 100 KW.

[0005]

In the fuel cell described above, the peak outputs W1, W
It is known that the power generation efficiency is reduced in a region of 20% or less with respect to the output of No. 2 and the power generation efficiency is significantly reduced in a region of 10% or less of the output of the peak outputs W1 and W2. I have. For a fuel cell system mounted on a large vehicle, a fuel cell system having a peak output of 200 to 300 KW is required.

[0006] Therefore, this fuel cell system is used, for example, in a range of 20 KW to 30 KW for operating only auxiliary equipment such as a refrigerator.
When the operation is performed with the load output of W, an operation state where the power generation efficiency is poor is obtained. The present invention provides a vehicular fuel cell system that solves the above-mentioned problems.

[0007]

A fuel cell system for a vehicle according to the present invention comprises two rows of fuel cells connected in parallel, and two air compressors connected to each row of fuel cells and supplying air. A control valve for controlling a flow rate of fuel supplied to the fuel cell; a control device; and a drive device for a vehicle driven by an output from the fuel cell. When the output request value for the entire fuel cell becomes 20% or less of the maximum output value, the control device stops the operation of one of the two rows of fuel cells and doubles the other fuel cell. It is operated by output.

[0008]

FIG. 1 is a block diagram of a vehicle fuel cell system according to the present invention. A vehicular fuel cell system generally designated by the reference numeral 100 includes a first row of fuel cells 110 and a second row of fuel cells 120 arranged in parallel with the first row of fuel cells 110.

The first row of fuel cells 110 is composed of a plurality of fuel cell stacks connected in series as described with reference to FIG. 3, for example. The second row of fuel cells 120 has a similar structure. The hydrogen tank 130 sends hydrogen as fuel to the anode 114 of the first row of fuel cells 110 via the line 131. In the middle of the line 131, a control valve 141 for controlling the flow rate of the supplied hydrogen is provided.

Similarly, the hydrogen from the hydrogen tank 130 is
The fuel is supplied to the anode 124 of the second row of fuel cells 120 via the line 132. A control valve 14 for controlling the flow rate of the supplied hydrogen is provided in the middle of the line 132.
These control valves 141 and 142 are connected to a control device 180, and the opening is controlled by signals S1 and S2.

The first compressor 150 is driven by a motor 152 to draw air A through a filter 154 and pressurize the air. The pressurized air passes through the heat exchanger 156 and is supplied to the cathodes 112 of the first row of fuel cells 110.

The anode 114 of the first row fuel cell 110
Is discharged to the burner B1 for combustion and heat exchange. The exhaust E1 discharged from the cathode 112 is discharged to the outside. First row fuel cell 110
The first output W1 generated by the vehicle driving device 160
Sent to

The voltage V1 of the first output W1 and the current I
1 is sent to the control device 180 and detected by the control device 180. Motor 152 for driving first compression 150
Is connected to the control device 180 and is driven by the driving pressure D1.

The second compressor 160 is driven by a motor 162 to draw air A through a filter 164 and pressurize the air. The pressurized air passes through the heat exchanger 166 and is supplied to the cathodes 122 of the first row of fuel cells 120.

The anode 124 of the second row of fuel cells 120
Is discharged to the burner B1 for combustion and heat exchange. The exhaust E1 discharged from the cathode 122 is discharged to the outside. Second row fuel cell 120
The first output W2 generated by the vehicle driving device 160
Sent to

The voltage V2 and the current I of the second output W2
2 is sent to the control device 180 and detected by the control device 180. Motor 162 for driving second compression 160
Is connected to the control device 180 and is driven by the driving pressure D2.

The driving device 170 is a driving motor 1 for a vehicle.
72, and a drive motor control circuit 174.
80. The control device is a CPU 182, a ROM
184, a RAM 186, an input / output processing circuit 188, and the like, and executes output control of the fuel cell system 100 in response to an output request signal C1 from the driver's seat.

FIG. 2 is a flowchart of a control process of the vehicle fuel cell system of the present invention. The processing started in step S10 is the same as that in step S11.
The output voltage V1 and the output current I1 of 0 are read. Step S1
2, the current output Wn is reduced to the output voltage V1 by the output current I1.
Multiplied by. In step S13, the average output Wm
Is calculated by the following equation: Wm = K (Wn−W0) + W0.

Here, K is an averaging coefficient, and is 0 to 1.0.
Any value of is selected. W0 is an average output value of outputs calculated at the time of the previous detection, and is, for example, a value 10 ms before. In step S14, the average output Wm is compared with the maximum output of the fuel cell in the first row, and it is determined whether the average output Wm is less than 20% of the maximum output. Average output Wm is 2 of maximum output
If it is 0% or less, the process proceeds to step S15, and a signal D1 of zero output is sent to the motor 152 of the first compressor 150. At the same time, the closing signal S is supplied to the first hydrogen control valve 141.
Send 1 to cut off the hydrogen supply. By this process, the power generation of the first row of fuel cells is stopped.

Next, the process proceeds to step S16, where an output signal D2 corresponding to a double fuel cell output request is sent to the motor 162 of the second compressor 160. At the same time, the valve opening value signal step S2 corresponding to the double fuel cell output request is sent to the second hydrogen control valve 142 to increase the supply amount of hydrogen. By this processing, the output of the fuel cell 160 in the second column is increased by a factor of two. In step S17, W0 is replaced with Wm, and the process ends in step S18.

In the above-described processing, the output of the fuel cell in the first column is detected to utilize the fuel cell in the second column. Naturally, it is possible to utilize the first row of fuel cells upon detection.

[0022]

According to the fuel cell system for a vehicle of the present invention,
The fuel cells in the rows are connected in parallel, and a device for supplying hydrogen fuel and air to the fuel cells in each row is separately equipped.
When maximum output is required, the outputs of the two rows of fuel cells are supplied to the drive. The required output is the maximum output,
For example, when it is 20% or less, it is sent to one fuel cell column. By shutting off the hydrogen fuel and air and increasing the amount of hydrogen fuel and air sent to the other fuel cell train to a value corresponding to twice the output, the fuel cell is used in a region where the output efficiency is high. Thereby, the operation efficiency of the fuel cell system for a vehicle can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle fuel cell system of the present invention.

FIG. 2 is a flowchart of control processing of the vehicular fuel cell system of the present invention.

FIG. 3 is an explanatory diagram of a fuel cell stack configuration.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 vehicle fuel cell system 110 first row fuel cell 112 first row fuel cell cathode 114 first row fuel cell anode 120 second row fuel cell 122 second row fuel cell cathode 124 second Row fuel cell anodes 130 Hydrogen tank 141 First control valve 142 Second control valve 150 First air compressor 152 First air compressor motor

Claims (1)

[Claims] 1. Two rows of fuel cells connected in parallel, two air compressors connected to each row of fuel cells to supply air, and controlling the flow rate of fuel supplied to the fuel cells. A control valve, a control device, and a drive device for a vehicle driven by an output from the fuel cell. The control device is configured to output a signal when the required output value to the entire fuel cell becomes 20% or less of the maximum output value. A vehicular fuel cell system in which one of the fuel cells in a row stops operating and the other fuel cell operates at twice the output.