JP2002151130A - Fuel cell vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of a fuel cell caused by suction of a hazardous substance such as CO when running. SOLUTION: In a hybrid fuel cell vehicle having a fuel cell 200 and a secondary battery 207 as a power source for a motor 208, two intake parts 250, 260 selectively connected to a compressor 202 through a change-over valve 270 are installed in the different positions of the vehicle, and by sucking the air through the intake part having lower CO concentration based on a result detected with CO sensors 251, 262 installed in the intake parts, deterioration of the fuel cell caused by CO is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vehicle equipped with a fuel cell as a power source.

[0002]

2. Description of the Related Art In fuel cells, solid oxide type, molten carbonate type, phosphoric acid type,
There are several types such as solid polymer type and alkali type. Polymer electrolyte fuel cells that use fluorine-based ion-exchange membranes as electrolytes have been able to obtain many times higher current densities than ever before with the realization of high-performance ion-exchange membranes. In the mounting space,
It is becoming possible to mount a fuel cell with a sufficient output. On the other hand, ZEV (Zero
The application of polymer electrolyte fuel cells to electric vehicles has begun to be considered in earnest due to regulations on emission vehicles, but to date no fuel cell vehicles have been put on the market. It is only the stage where the car is open.

An electric vehicle equipped with a fuel cell includes a fuel cell that generates power using fuel and air mainly composed of hydrogen, an air supply device that supplies air to the fuel cell, and a fuel gas containing hydrogen in the fuel cell. In general, the fuel supply device is configured to include a fuel supply device to be supplied, a motor that converts electric power into driving force, and the like, and has a hybrid configuration of a fuel cell and a secondary battery. Broadly speaking, as a fuel supply system, a system for storing and supplying hydrogen itself or a system for converting and supplying a fuel such as methanol or gasoline to a reformed gas containing hydrogen using a reformer is being studied. .

[0004]

As described above, when a fuel cell vehicle using a polymer electrolyte fuel cell as a power source of a moving body travels in a tunnel, a conventional internal combustion engine is used as a power source. There is a problem in that exhaust such as NOx and oil components emitted from a vehicle (engine vehicle) is sucked by a compressor as an air supply device and supplied to a fuel cell.

For example, as shown in FIG.
The inside of 06 is an environment where exhaust gas is likely to be filled by the running of the engine vehicle 105. When the fuel cell vehicle 103 travels in such a tunnel, the compressor 101
Sucks exhaust gas through the filter 102 and supplies it to the fuel cell 100. 104 is a housing of the fuel cell system. Of the engine emissions, Nox is taken into the aqueous system as nitric acid or nitrous acid in the polymer membrane of the fuel cell stack swelled with moisture, and its oxidizing properties degrade various materials and the polymer membrane of the stack. Therefore, the stack performance is degraded. Further, since the replacement time of the water-based deionization filter is hastened, there is a problem that the maintenance cost is increased. In addition, the oil component of the exhaust gas adsorbs on the electrode catalyst of the fuel cell, deteriorating the electrode catalyst performance and deteriorating the stack performance. As a countermeasure, increasing the performance of the air filter not only increases the manufacturing cost and maintenance cost, but also increases the pressure loss of the air filter, which increases the operating power of the compressor and reduces the fuel efficiency of the fuel cell vehicle. I will.

Japanese Unexamined Patent Application Publication No. 9-90905 addresses such various problems caused by substances harmful to fuel cells contained in the air.
No. 63620 proposes a configuration in which means for oxidizing carbon monoxide (CO) in intake air is provided. In this case, there is a problem that extra fuel is necessary to heat the air once with the heating burner, and the radiator heat dissipation increases to cool the air once heated. Fuel cells operate at low temperatures and have the advantage of being able to start at room temperature, but at the same time have the characteristic of producing a large amount of exhaust heat that is difficult to dissipate into the air at low temperatures. Mounting is an important issue related to the feasibility of a car. In addition, it is difficult to oxidize and remove oil in the atmosphere, and it is basically impossible to oxidize and remove NOx, and it is necessary to decompose and remove it into nitrogen and oxygen. It is very difficult to promote a decomposition reaction, which is a reduction reaction, in an oxidizing atmosphere, which is an atmosphere containing a large amount of oxygen.

On the other hand, on-site fuel cell power plants also have various problems caused by inhaling harmful substances.
No. 0744 proposes a configuration in which means for detecting harmful substances is provided, and power generation is stopped when inhalation of harmful substances is detected. However, in such a configuration, when applied to a fuel cell vehicle that is a moving body, there is a problem that the running performance is reduced depending on the situation.

The present invention has been made in view of such a conventional problem, and a plurality of intake portions are provided in an air supply device of a fuel cell device, and each of the intake portions is provided in accordance with the amount of harmful substances in the intake air. It is an object of the present invention to provide a fuel cell vehicle in which a fuel cell device can be operated under better conditions by switching an intake section.

[0009]

According to a first aspect of the present invention, there is provided a fuel cell for generating electricity by using fuel and air mainly composed of hydrogen, an air supply device for supplying air to the fuel cell, and A fuel supply device that supplies a fuel gas containing hydrogen, a motor that converts electric power generated by the fuel cell into driving power, and stores electric power generated by the fuel cell or regenerative electric power by the motor, and And a secondary battery that supplies the motor to the motor, the intake unit of the air supply device is provided at a plurality of locations of the vehicle, and each of the intake units can be selected via a switching valve, Harmful substance detection means for detecting a harmful substance with respect to the fuel cell device in the air taken in by each intake section provided in each intake section, and detection based on a detection result of the harmful substance detection means. Relatively small intake section harm substance amount is assumed that a control unit for controlling the switching valve so as to connect to the air supply device.

A second invention provides the control means according to the first invention, wherein when there are a plurality of intake parts whose detected harmful substance amounts are equal to or less than a predetermined reference value, the ram pressure of the plurality of intake parts is reduced. It is configured to switch to a large intake section.

According to a third aspect of the present invention, the control means according to the second aspect of the present invention comprises a ram pressure detecting means for detecting a ram pressure of each intake section, and a ram pressure detecting section of the plurality of intake sections based on the detected ram pressure. It is assumed that the intake section having a large pressure is switched.

According to a fourth aspect of the present invention, the control means of the first aspect of the present invention is configured such that the fuel cell is stopped when the detected harmful substance amounts in the plurality of intake units are all equal to or greater than a predetermined reference value. I do.

[0013] In a fifth aspect based on the fourth aspect,
A secondary battery remaining amount detecting means for detecting a remaining amount of the secondary battery, wherein when the detected remaining amount of the secondary battery is equal to or less than a reference value, the fuel cell is operated regardless of the detected harmful substance amount. It shall be configured.

According to a sixth aspect, in the first aspect,
It comprises a secondary battery remaining amount detecting means for detecting the remaining amount of the secondary battery, and when the detected secondary battery remaining amount exceeds a reference value,
It is assumed that the operation of the fuel cell is stopped regardless of the detected harmful substance amount.

According to a seventh aspect, the control means of the first aspect controls the operation or stop of the fuel cell based on the time average of the concentration of harmful substances and the remaining amount of the secondary battery. And

According to an eighth aspect of the present invention, the control means of the fifth or sixth aspect refers to a map in which a fuel cell operation area or a stop area is set using the harmful substance concentration and the remaining amount of the secondary battery as parameters. In this case, the operation or stop of the fuel cell is controlled.

In a ninth aspect, the control means according to the fifth or sixth aspect is configured to control the operation or stop of the fuel cell by controlling the operation of the reformer for generating hydrogen. And

In a tenth aspect, the control means according to the fifth or sixth aspect is configured to control the operation or stop of the fuel cell by controlling the supply of stored hydrogen to the fuel cell. .

According to an eleventh invention, the harmful substance detecting means of the first invention is characterized in that at least carbon monoxide is used as a harmful substance.
It is assumed that one of NOx and an oil component is detected.

[0020]

According to the first and second aspects of the invention,
During operation of the fuel cell, the air supply device sucks the operating atmosphere from any of the plurality of intake portions. At this time, the amount (or concentration) of the harmful substance such as CO is detected by the harmful substance detection means provided in each of the intake sections, and the intake section and the air supply section having a relatively small amount of the detected harmful substance are connected. ,
The control means controls the switching valve to perform switching. In other words, the switching control of the plurality of intake portions always supplies the fuel cell device with the atmosphere having a relatively small amount of harmful substances.
Thereby, deterioration of the fuel cell is suppressed.

According to the second aspect, when there are a plurality of intake sections whose detected harmful substance amounts are equal to or less than a predetermined reference value, the intake section having a relatively high ram pressure (running pressure) among the plurality of intake sections. Switching to the section reduces the driving load on the air supply device, which is advantageous in terms of efficiency of the fuel cell device. In this case, the magnitude relationship of the ram pressure can be determined from a relationship experimentally obtained in advance. However, the third
As shown in the invention of the above, it is also possible to provide ram pressure detecting means for detecting the ram pressure of each intake section, and to switch to the intake section having a relatively high ram pressure based on the detected ram pressure. According to this, even when the ram pressure changes according to the running conditions of the vehicle, it is possible to accurately select the intake portion having a high ram pressure.

According to the fourth aspect, the fuel cell is stopped when all the detected harmful substance amounts in the plurality of intake portions are equal to or greater than the predetermined reference value. Can be prevented. Further, according to the fifth aspect, when the remaining amount of the secondary battery is equal to or less than the reference value, the fuel cell is operated regardless of the detected harmful substance amount. It is possible to avoid a situation in which the operation of the vehicle becomes difficult due to the stop of the fuel cell under the conditions. According to the sixth invention, when the remaining amount of the secondary battery exceeds the reference value in the first invention, the operation of the fuel cell is stopped regardless of the detected harmful substance amount. When the remaining amount of the secondary battery does not impair the traveling function of the vehicle, the deterioration of the fuel cell can be suppressed by minimizing the driving opportunity of the fuel cell.

In the fuel cell operation / stop control as described above, as described in the eighth aspect, the operation area or the stop area of the fuel cell is set using the harmful substance concentration and the remaining amount of the secondary battery as parameters. By providing a map and determining whether to operate or stop the fuel cell with reference to the map, the operation can be performed relatively easily. On the other hand, when the operation or stop of the fuel cell is controlled based on the time average value of the concentration of harmful substances as in the seventh invention, when the vehicle passes a vehicle that emits a relatively large amount of harmful substances, for example, It is possible to prevent the energy efficiency from being lowered due to the instantaneous switching of the operation and stop of the fuel cell due to the instantaneous increase and decrease of the harmful substance concentration.

In order to operate or stop the fuel cell, as shown in the ninth or tenth invention, in the case of a fuel cell device having a reformer for generating hydrogen,
The control can be performed by controlling the operation of the reformer or, in the case of a device having means for storing hydrogen to be supplied to the fuel cell, by controlling the supply of stored hydrogen.

In each of the above inventions, it is desirable to detect at least carbon monoxide as the harmful substance, for example, as shown in the eleventh invention.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. In the figure, reference numeral 200 denotes a fuel cell that generates power using fuel gas containing hydrogen and air, 2
Reference numeral 01 denotes a reforming apparatus for reforming a fuel (for example, methanol or gasoline as a liquid fuel) to convert the fuel into a reformed gas containing hydrogen and supplying the reformed gas to a fuel cell 200;
Compressor as an air supply device for supplying air to the
5 is a fuel supply device for supplying fuel and water required for fuel reforming as required, 208 is a traveling motor of the vehicle, 207 is electric power generated by the fuel cell 200 or the traveling motor 208 reverses when the deceleration occurs. A battery (secondary battery) that stores regenerative electric power generated when driven or supplies electric power for traveling to the traveling motor 208.
This is a power control device that controls the exchange of various types of power, such as the power generated by the power generation 00, the power of the battery 207, the driving power of the driving motor 208, and the regenerative power, and the amount of power taken from the fuel cell 200. The power control device 209
Is the battery state SOC including the remaining amount of the battery 207
(State Of Charge) is calculated.

Reference numerals 250 and 260 are CO sensors provided as harmful substance detecting means, respectively. The first CO sensor 250 detects the concentration of CO in the air taken in at the first intake section 251 of the compressor 202, whereas the second CO sensor 250
The CO sensor 260 of the second intake section 26 of the compressor 202
In step 1, the CO concentration in the air taken in is detected. The first intake unit 251 is installed, for example, in the engine room of the vehicle in a forward direction, or is installed in an air intake on the bonnet facing the front of the vehicle, or a C pillar (part C in FIG. 1). (Refer to the above.) Install it in a place where it receives ram pressure when the vehicle runs, such as by installing it on an air intake facing the front of the vehicle. The second intake section 261 is provided with an A pillar (FIG. 1).
(See section A of the above.) It is installed in a place where it is difficult to directly inhale the exhaust gas of another vehicle above the vehicle, such as by installing it in an air intake above the vehicle.

A control means constituted by a microcomputer or the like based on the CO concentration signals Sa (252) and Sb (262) of the CO sensors 250 and 260 and the SOC signal 253 of the battery 207 calculated by the power control device 209. The controller 254 controls the switching operation of the switching valve 270 and the operation and operating states of the reformer 201, the compressor 202, the fuel supply device 205, and the fuel cell 200.

Next, the operation of the controller 254 will be described with reference to FIG. FIG.
4 represents a processing routine that is periodically executed by the microcomputer constituting the microcomputer 4. The letter “S” in the figure or in the following description indicates the processing step. S1: CO concentration signal Sa25 of the first CO sensor 250
2 is read and stored in the memory area. S2: CO concentration signal Sb26 of the second CO sensor 260
2 is read and stored in the memory area. S3: CO concentration signal Sa252 and CO concentration signal Sb26
Compare 2. S4 to S5: If the signal value of the CO concentration signal Sa252 is lower, the switching valve 270 is switched to the intake unit 251 and CO
The signal value of the density signal Sa252 is stored in a variable X. S6 to S7: If the signal value of the CO concentration signal Sb262 is lower, the switching valve 270 is switched to the intake section 261 and the CO
The signal value of the density signal Sb262 is stored in a variable X. S8: Battery 20 calculated by power control system 209
7 is read. S9: The operation and the stop of the reforming system 201 are determined with reference to the map A set as shown in FIG. S10 to S11: If the determination in S9 is "operate", nothing is performed if the reforming apparatus 201 is operating, and if the reforming apparatus 201 is stopped, the reforming apparatus 201 is restarted. Then, the current process is terminated. S12 to S13: If the determination in S9 is “do not run”, nothing is performed if the reformer 201 is stopped, and if the reformer 201 is running, stop processing of the reformer 201 is performed. Then, the current process ends.

The map A in FIG. 4 will be described.
The following operating conditions are assigned to this map in accordance with the secondary battery remaining amount SOC and the CO concentration. That is, if the SOC signal is equal to or less than the first reference value SOC_L, the C
The reformer 201 is operated regardless of the O concentration, and the fuel cell 2
00 is generated. On the other hand, the second reference value SOC_ in which the SOC signal is set higher than the first reference value
If it is equal to or higher than H, a sufficient driving force can be secured for the time being only by the battery 207. Therefore, the reformer 201 is stopped regardless of the CO concentration in the air taken in by the compressor 202.

FIG. 5 shows a second embodiment of the processing routine executed by the controller 254.
Hereinafter, the processing steps will be described step by step. S1: CO concentration signal Sa25 of the first CO sensor 250
2 is read and stored in the memory area. S2: CO concentration signal Sb26 of the second CO sensor 260
2 is read and stored in the memory area. S3: CO concentration signal Sa252 and CO concentration signal Sb26
By using the value of the signal of No. 2 and switching to one of the intake units 251 or 261 with reference to the map B shown in FIG. S4 to S5: When the area A is on the map B,
The switching valve 270 is switched to the first intake unit 251 and the signal value of the CO concentration signal Sa252 is stored in the variable X. S6 to S7: When the area B corresponds to the map B, the switching valve 270 is switched to the large intake section 261 and the signal value of the CO concentration signal Sb262 is stored in the variable X. S8: The SOC signal 253 of the battery 207 calculated by the power control device 209 is read. S9: The operation and the stop of the reformer 201 are determined with reference to the map A in FIG. S10 to S11: If the determination in S6 is "run", nothing is performed if the reforming apparatus 201 is operating, and if the reforming apparatus 201 is stopped, the reforming apparatus 201 is restarted. Then, the current process is terminated. S12 to S13: If the determination in S6 is "no operation", nothing is performed if the reforming apparatus 201 is stopped, and if the reforming apparatus 201 is operating, stop processing of the reforming apparatus 201 is performed. Then, the current process ends.

The map B in FIG. 6 will be described.
In this map, conditions for selecting which intake unit should be selected according to the CO concentration (Sa, Sb) in the intake air in each intake unit 251 and 261 are assigned.
If the O concentration is equal to or less than the preset allowable value Ss,
The first intake section 251 to which a relatively large ram pressure acts is selected, and when the CO concentration in the intake air exceeds the allowable value Ss, the second intake section 261 is selected by giving priority to the CO concentration.

According to the second embodiment, when the CO concentration is low, the ram pressure is prioritized and the intake section is selected, so that the driving load of the compressor 202 is reduced and the fuel cell system is reduced. Efficiency can be improved.

When the CO concentration in the air increases instantaneously, such as when passing through a diesel vehicle, the reformer 20
If the stop and re-start processing of Step 1 are performed frequently, the energy efficiency may decrease.
By performing control using the time average value of the O concentration, it is possible to suppress such a sensitive operation and secure high efficiency. Although the CO sensor is exemplified as the harmful substance detection means of the embodiment, the same control can be performed by means of detecting other harmful substances. Also, the present invention
The present invention is not limited to the reformed fuel cell vehicle described in the embodiment, and is applicable to a direct hydrogen fuel cell vehicle having a storage system for hydrogen itself.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an environmental state when a fuel cell vehicle runs with a conventional engine vehicle.

FIG. 2 is a block diagram showing a configuration concept of an embodiment of a fuel cell vehicle according to the present invention.

FIG. 3 is a flowchart showing control contents of the embodiment.

FIG. 4 is an explanatory diagram showing a configuration example of a map used for control in the embodiment.

FIG. 5 is a flowchart showing a second embodiment relating to control contents.

FIG. 6 is an explanatory diagram showing a configuration example of a map used for control in the second embodiment.

[Explanation of symbols]

 Reference Signs List 200 fuel cell 201 reformer 202 compressor (air supply device) 205 fuel supply device 207 battery (secondary battery) 208 traveling motor 209 power control device 250 first CO sensor 251 first intake unit 260 second CO Sensor 261 Second intake unit 254 Controller (control means)

Claims (11)

[Claims] 1. A fuel cell for generating electricity by using fuel and air mainly composed of hydrogen, an air supply device for supplying air to the fuel cell, and a fuel supply for supplying the fuel gas containing hydrogen to the fuel cell A device, a motor that converts power generated by the fuel cell into driving power, and a secondary battery that stores power generated by the fuel cell or regenerative power by the motor and supplies the power to the motor. In the fuel cell vehicle provided with, the intake unit of the air supply device is provided at a plurality of locations of the vehicle, and each of the intake units can be selected via a switching valve, and the intake unit is provided for each of the intake units A harmful substance detecting means for detecting a harmful substance to the fuel cell device in the air sucked in at the time of detecting the harmful substance in the plurality of intake portions based on a detection result of the harmful substance detecting means; Fuel cell vehicles but a relatively small intake unit has a control unit for controlling the switching valve so as to connect to the air supply device. 2. The fuel cell vehicle according to claim 1,
The fuel cell vehicle, wherein the control means is configured to, when there are a plurality of intake parts whose detected harmful substance amounts are equal to or less than a predetermined reference value, switch to an intake part having a higher ram pressure among the plurality of intake parts. . 3. The fuel cell vehicle according to claim 2,
The control unit includes a ram pressure detecting unit that detects a ram pressure of each intake unit, and is configured to switch an intake unit having a large ram pressure among the plurality of intake units based on the detected ram pressure. Fuel cell vehicle. 4. The fuel cell vehicle according to claim 1, wherein
A fuel cell vehicle configured to stop the fuel cell when all of the detected harmful substance amounts in the plurality of intake sections are equal to or greater than a predetermined reference value. 5. The fuel cell vehicle according to claim 4, wherein
A secondary battery remaining amount detecting means for detecting a remaining amount of the secondary battery, wherein when the detected remaining amount of the secondary battery is equal to or less than a reference value, the fuel cell is operated regardless of the detected harmful substance amount. Fuel cell vehicle configured. 6. The fuel cell vehicle according to claim 1, wherein
It comprises a secondary battery remaining amount detecting means for detecting the remaining amount of the secondary battery, and when the detected secondary battery remaining amount exceeds a reference value,
A fuel cell vehicle configured to stop operation of a fuel cell irrespective of a detected harmful substance amount. 7. The fuel cell vehicle according to claim 5, wherein the control means controls the operation or stop of the fuel cell based on the time average of the concentration of the harmful substance and the remaining amount of the secondary battery. A fuel cell vehicle configured to: 8. A fuel cell vehicle according to claim 5, wherein said control means sets a fuel cell operation area or a stop area using the harmful substance concentration and the remaining amount of the secondary battery as parameters. A fuel cell vehicle configured to control the operation or stop of the fuel cell with reference to FIG. 9. The fuel cell vehicle according to claim 5, wherein the control means controls operation or stop of the fuel cell by controlling operation of a reformer for generating hydrogen. Fuel cell vehicle configured. 10. The fuel cell vehicle according to claim 5, wherein the control means controls the operation or stop of the fuel cell by controlling the supply of stored hydrogen to the fuel cell. Fuel cell vehicle. 11. The fuel cell vehicle according to claim 1, wherein said harmful substance detection means detects at least one of carbon monoxide, NOx, and an oil component as a harmful substance.