JP2004074992A - Air-conditioner of fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioner of a fuel cell vehicle for rapidly raising the temperature of a fuel cell. <P>SOLUTION: The air-conditioner 2 of the fuel cell vehicle 1 performs heating by supplying power to an electric heater 8 by power generated by a fuel cell 3. A control device 9 to control the power to the electric heater 8 according to the outside temperature of the vehicle 1 and the temperature of the fuel cell 3 is provided. The control device 9 controls to reduce the power to the electric heater 8 according to the outside temperature in a regular state that the temperature of the fuel cell 3 is higher than a predetermined value, and the control device, on the other hand, controls to increase the power to the electric heater 3 compared with the regular state irrespective of the outside temperature in a cold state that the temperature of the fuel cell 3 is lower than a predetermined value. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner for a fuel cell vehicle that performs heating by supplying electric power to an electric heater using electric power generated by a fuel cell.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a fuel cell vehicle equipped with a solid polymer membrane type fuel cell (hereinafter, appropriately referred to as “vehicle”), a hybrid type in which a fuel cell (FC) and a capacitor are combined is known.
In this hybrid fuel cell vehicle, the power generated by the fuel cell is supplemented by a capacitor to supply necessary electric power to an electric auxiliary device such as a drive motor or an air conditioner.
[0003]
2. Description of the Related Art As a heating device for a fuel cell vehicle, there is a heating device that supplies electric power generated by a fuel cell to an electric heater to heat a vehicle interior.
As the temperature control of the heating device, the amount of electricity supplied to the electric heater is controlled based on the target relationship between the cabin temperature and the outside air temperature. The heater power is set to decrease.
[0004]
[Problems to be solved by the invention]
Conventional electric heaters are controlled so as to satisfy only the heating performance of the vehicle.
After the fuel cell is stopped, the fuel cell is cooled by the outside air temperature. Therefore, when the fuel cell vehicle is started (start of power generation) in the early morning, the outside air temperature and the temperature of the fuel cell are almost equal. However, the temperature of the fuel cell does not rise immediately with the subsequent rise in the outside air temperature.
Therefore, in such a state where the outside air temperature is relatively high and the temperature of the fuel cell is low, a conventional electric heater that is controlled to satisfy only the heating performance of the vehicle does not have the fuel cell. It could not contribute to the early warm-up.
[0005]
The present invention has been made in view of the circumstances described above, and has as its object to provide an air conditioner for a fuel cell vehicle for achieving both heating performance of the vehicle and early warm-up performance of the fuel cell. .
[0006]
[Means for Solving the Problems]
The present invention has been made to achieve the above object, and in an air conditioner for a fuel cell vehicle that performs heating by supplying electric power to an electric heater with power generated by a fuel cell, an outside air temperature of the vehicle, A control unit (for example, the control device 9 in the embodiment) for controlling the power supplied to the electric heater according to the temperature of the fuel cell is provided. As the outside air temperature increases, the supply power to the electric heater is reduced, and when the temperature of the fuel cell is lower than a predetermined value in a cold state, the supply power to the electric heater is increased from the normal time regardless of the outside air temperature. Control is performed.
[0007]
According to the present invention, when the temperature of the fuel cell is in a normal state higher than the predetermined value, the power supplied to the electric heater is reduced as the outside air temperature increases (economy operation is performed). As a result, the power consumption of the air supply compressor for power generation is reduced, so that the consumption of hydrogen fuel and the vibration and noise of the vehicle caused by driving the compressor can be reduced.
On the other hand, when the temperature of the fuel cell is in a cold state lower than a predetermined value, the power supplied to the electric heater is increased from the normal state regardless of the outside air temperature. The self-heating value of the battery increases, and the warm-up performance of the fuel cell can be improved, and early warm-up can be promoted.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing a fuel cell vehicle 1 according to an embodiment of the present invention. FIG. 2 is a block diagram of the air conditioner 2 of the fuel cell vehicle 1. The illustration of the current limiting device 7 and the control device 9 is omitted in FIG.
The air conditioner 2 according to the present embodiment includes a hybrid power supply device including, for example, a fuel cell 3 and a capacitor 4 that is a power storage device.
[0009]
The fuel cell 3 has a structure in which a plurality of fuel cells in each of which a solid polymer electrolyte membrane is sandwiched between an anode electrode and a cathode electrode are laminated and integrated, and as shown in FIG. It is located below the floor.
[0010]
The anode electrode of the fuel cell 3 is supplied with hydrogen gas from a hydrogen tank (not shown), and the cathode electrode is supplied with oxidant gas (air containing oxygen) from an air compressor (not shown). When hydrogen is supplied to the reaction surface of the anode electrode, the hydrogen is ionized here and moves toward the cathode electrode through the solid polymer electrolyte membrane. The electrons generated during this time are taken out to an external circuit and used as DC electric energy.
[0011]
A current limiting device 7 is connected to the fuel cell 3. The current limiting device 7 is also connected to the capacitor 4, the driving motor 5, and the electric heater 8 mounted on the air conditioner 6, and limits the output from the fuel cell 3 as necessary, and 5, 6, and 8.
[0012]
The current limiting device 7 is also connected to an air compressor motor (not shown) that drives an air compressor for supplying a reaction gas (oxidant gas) to the fuel cell 3. Therefore, a part of the electric power generated by the fuel cell 3 is used to drive an air compressor that supplies a reaction gas (oxidizing gas).
In addition, the current limiting device 7 is connected to an electric accessory such as a headlamp in addition to the air conditioner 6 and the electric heater 8, and supplies electric power to each electric accessory.
[0013]
The capacitor 4 is, for example, an electric double-layer capacitor, is charged with the generated current of the fuel cell 3, and supplies power to electric auxiliary machines such as a driving motor 5 and an air conditioner 6 while assisting the fuel cell 3. .
[0014]
The driving motor 5 generates a driving force by electric power supplied from the fuel cell 3 and the capacitor 4, and the driving force is transmitted to driving wheels (not shown) via a reduction or transmission T / M. As a result, the fuel cell vehicle 1 runs.
[0015]
When the driving force is transmitted from the driving wheels to the driving motor 5 at the time of deceleration of the fuel cell vehicle 1, the driving motor 5 functions as a generator and generates a so-called regenerative braking force. Thereby, the kinetic energy of the vehicle body can be recovered as electric energy, and the electric energy is stored in the capacitor 4.
[0016]
The air conditioner 6 is for adjusting the air inside the vehicle 1. By activating the electric heater 8 mounted on the air conditioner 6, the air inside the vehicle 1 can be heated. it can. Therefore, the temperature inside the vehicle 1 can be adjusted according to the electric power supplied to the electric heater 8.
[0017]
A control device 9 is connected to the fuel cell 3, the current limiting device 7, the driving motor 5, and the electric heater 8. The control device 9 calculates the electric power required for operating the electric accessory from the accelerator pedal depression amount Ap and the vehicle speed Vc, and based on the calculated electric power, the fuel cell 3, the current limiting device 7, the driving motor 5. Send control signals to the air conditioner 6 equipped with the electric heater 8 respectively.
[0018]
Specifically, the target power generation amount is transmitted from the control device 9 to the fuel cell 3, and the amount of reaction gas supplied to the fuel cell 3 is controlled according to the target power generation amount. Further, a current value is transmitted from the control device 9 to the current limiting device 7, whereby the current limiting device 7 restricts the power generated by the fuel cell 3 so as to have the current value. The air is supplied to an air conditioner 6 equipped with a driving motor 5 and an electric heater 8. In addition, the control device 9 transmits a drive power amount to the drive motor 5, whereby the drive power is limited as required. Then, an operation signal is transmitted to the air conditioner 6 on which the electric heater 8 is mounted, and the air conditioner 6 and the electric heater 8 are operated in response thereto.
[0019]
Further, the fuel cell 3 is provided with a temperature sensor S1 for measuring its temperature, and the temperature of the fuel cell 3 measured by the temperature sensor S1 is transmitted to the control device 9. The mounting position of the temperature sensor S1 may be on a circulating water (cooling water) path discharged from the fuel cell 3 or on a reacted gas (off gas) path discharged from the fuel cell 3. . Further, the vehicle 1 is provided with an outside air temperature sensor S2, and the outside air temperature measured by the outside air temperature sensor S2 is transmitted to the control device 9. The control device 9 performs the following control based on the temperatures transmitted from the temperature sensors S1 and S2.
[0020]
FIG. 3 is a flowchart of the air conditioner 2 of the fuel cell vehicle 1 according to the present embodiment. First, in step S02, it is determined whether or not the outside air temperature of the vehicle 1 detected by the outside air temperature sensor S2 is higher than a predetermined value (for example, 0 degree). If the result of the determination is YES, it is necessary to rapidly warm up the interior of the vehicle 1 and therefore the process of step S04 is performed. This will be described with reference to FIG.
[0021]
FIG. 4 is a graph showing the relationship between the outside air temperature and the target power consumption of the air conditioner 6. In the figure, the horizontal axis is the outside air temperature of the vehicle 1, and the horizontal axis is the target power consumption of the electric heater 8. As shown by the line L in FIG. 4, when the outside air temperature is equal to or lower than a predetermined value (in this case, 0 degree), in step S04, the power consumption of the electric heater 8 is set to the maximum value Pmax. As a result, the amount of heat generated by the electric heater 8 mounted on the air conditioner 6 is maximized, and the interior of the vehicle 1 is quickly heated.
[0022]
If the decision result in the step S02 is NO, a step S06 decides whether or not the temperature of the fuel cell 3 detected by the fuel cell temperature sensor S1 is equal to or higher than a predetermined value (for example, 0 degree). When the result of the determination is YES, the temperature of the fuel cell 3 is sufficiently high and there is no need for early warm-up, so there is no need to increase self-heating by the electric heater 8. In this case, in step S12, the power supplied to the electric heater 8 is reduced according to the level of the outside air temperature (see line N in FIG. 4). As described above, since the power supplied to the electric heater 8 for heating is reduced in accordance with the level of the outside air temperature, the amount of reaction gas required for power generation can be reduced, thereby improving fuel efficiency. It is possible to do.
[0023]
If the determination result in step S06 is NO, it means that the temperature of the fuel cell 3 is in a cold state lower than a predetermined value (0 degree), and the electric heater 8 causes the fuel cell 3 to increase its own heat generation. In this case, in step S08, the power supply to the electric heater 8 is increased from the normal time, so that the required power generation amount to the fuel cell 3 is increased from the normal time (see the line M in FIG. 4). Since the fuel cell 3 generates heat with power generation, the amount of heat generation can be increased by increasing the amount of power generation. As a result, the fuel cell 3 itself is quickly heated, and can be shifted from a cold state to a normal state at an early stage. In the present embodiment, in step S08, the power consumption of the electric heater 8 is set to be the maximum value Pmax, so that the fuel cell 3 itself can be heated more quickly.
[0024]
As described above, even when the temperature of the fuel cell 3 is in a cold state lower than the predetermined value, the fuel cell 3 can be quickly shifted to a normal state, and there is no need to supply an extra reactive gas as in the case of a cold state. Therefore, the fuel consumption can be improved, and the operation amount of the auxiliary equipment for the fuel cell, such as the air compressor, which supplies the reaction gas to the fuel cell, can be reduced as compared with when the engine is cold. Can be reduced. In addition, it is preferable to use the lower limit of the operating temperature of the fuel cell 3 (the temperature at which the reaction gas can be effectively used for power generation) as the predetermined value.
[0025]
After the temperature of the fuel cell 3 has become equal to or higher than the predetermined value by the above-described processing (steps S08 and S12), it is determined in step S14 whether or not the voltage value of the fuel cell has decreased. If a sudden load change is applied while the voltage of the fuel cell is decreasing, a heavy load is applied to the fuel cell 3, and the above determination is made to prevent this. If the result of the determination is YES, the operation of the electric heater 8 is stopped in step S16, and a series of processing ends. Thus, the amount of generated power required for the fuel cell 3 is reduced, and the burden on the fuel cell 3 can be reduced.
[0026]
If the determination result in step S14 is NO, the power that can be supplied to the electric heater 8 is set. Here, when the total electric power required for the electric accessories and the driving motor 5 is larger than the electric power that can be generated by the fuel cell 3, the electric power supplied to the electric heater 8 is limited (see P ′ in FIG. 4). . As a result, it is possible to prevent an excessive load from being applied to the fuel cell 3. When this process is performed, since the temperature inside the vehicle 1 is already higher than a certain level, there is no problem even if the power supplied to the electric heater 8 is limited.
[0027]
As described above, the air conditioner for a fuel cell vehicle according to the present invention has been described in the embodiment, but the present invention is not limited to this content. For example, a battery may be used instead of a capacitor.
[0028]
【The invention's effect】
As described above, according to the first aspect of the invention, the amount of the reaction gas used for power generation is reduced by reducing the power supplied to the electric heater for heating according to the level of the outside air temperature. This makes it possible to improve fuel efficiency. Further, in the cold state, the required power generation amount for the fuel cell is increased from the normal state by increasing the power supplied to the electric heater from the normal state, so that the fuel cell itself is quickly heated, The transition can be made from cold to normal. Therefore, the fuel efficiency can be improved, and the operation amount of the fuel cell auxiliary device can be reduced as compared with when the fuel cell is cold, so that the noise generated from the fuel cell auxiliary device can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an arrangement of an air conditioner of a fuel cell vehicle according to an embodiment of the present invention.
FIG. 2 is a block diagram showing an air conditioner of the fuel cell vehicle according to the present embodiment.
FIG. 3 is a flowchart of an air conditioner for a fuel cell vehicle according to the present embodiment.
FIG. 4 is a graph showing a relationship between an outside air temperature and a target power consumption of the air conditioner.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 fuel cell vehicle 2 air conditioner 3 fuel cell 6 air conditioner 8 electric heater 9 controller

Claims (1)

In an air conditioner of a fuel cell vehicle that performs heating by supplying electric power to an electric heater by power generated by a fuel cell,
Control means for controlling power supplied to the electric heater in accordance with the outside air temperature of the vehicle and the temperature of the fuel cell,
The control means includes:
At normal times when the temperature of the fuel cell is higher than a predetermined value, the power supplied to the electric heater is reduced as the outside air temperature increases,
An air conditioner for a fuel cell vehicle, wherein the control is performed such that the power supplied to the electric heater is increased from the normal time regardless of the outside air temperature when the temperature of the fuel cell is lower than a predetermined value.

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