JP2000059918A - Automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile with high energy efficiency, by converting kinetic energy at the time of braking the automobile into another type of energy and storing it, using both of a storage mechanism and a cold storage mechanism. SOLUTION: At the time of braking an automobile, a motor serves as a generator to convert kinetic energy into electric energy, and charge electric power into a battery 9 through a current/voltage control mechanism 4. A cooler 10 is operated by surplus current to generate cold and store it in a cold storage device 11. Otherwise, a heater 13 is operated by surplus current to generate heat and store it in a heat storage device 14. The cold stored in the cold storage device 11 can be used by a cold/heat dissipation device 12 for indoor cooling and a cold/heat dissipation device 7 for battery cooling to control the temperature of a battery 9. The heat stored in the heat storage device 14 can be used mainly by a radiator 15 for indoor heating and a radiator 8 for battery heating to control battery temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body such as an automobile or a train for obtaining all or a part of driving force by using battery energy, and to a system for improving energy efficiency.

[0002]

2. Description of the Related Art Conventionally, in an electric vehicle which obtains a driving force by a battery and a motor, when the vehicle is braked, the generator is turned by the kinetic energy of the vehicle to generate electric power, and the electric power is charged into the battery to increase energy efficiency. I was However, electric energy higher than the charge receiving performance and capacity of the battery is discarded outside by heating (for example, when the electric vehicle is traveling downhill when the battery is fully charged). Further, in a hybrid vehicle having an internal combustion engine, a motor and a battery, the energy efficiency is increased by turning a generator with the kinetic energy of the vehicle to generate power when braking the vehicle and charging the battery with the electricity. However, electric energy higher than the charge receiving performance and capacity of the battery is discarded outside by heating (for example, when the electric vehicle is traveling downhill when the battery is fully charged).

Further, a fuel cell vehicle equipped with a fuel cell, a battery, and a motor does not have a mechanism for converting kinetic energy of the vehicle into other energy, so that kinetic energy during braking cannot be recovered.

For example, Japanese Patent Application Laid-Open No. 6-319203 discloses an electric vehicle with an energy recovery device, which is provided with a mechanism for charging a storage battery with electric energy generated by an electric brake. In order to prevent the storage battery from being damaged by the current, a current exceeding the capacity of the storage battery is released to the outside as heat.

[0005]

In the above prior art, energy efficiency is not good in electric vehicles and hybrid vehicles because it is not possible to recover more energy than the battery's charge receiving performance and capacity. In addition, the fuel cell vehicle does not have a means for regenerating energy, and thus has a high energy efficiency.

Accordingly, an object of the present invention is to provide an automobile having high energy efficiency by converting kinetic energy during braking of the automobile into another form of energy and storing it.

[0007]

The above object can be achieved by simultaneously providing a heat storage mechanism and a cold storage heat mechanism. In this case, it is more effective to provide a heat generation mechanism and a cold heat generation mechanism that can be individually controlled. In order to more effectively control the heat storage mechanism, the cold storage heat mechanism, the heat generation mechanism, and the cold heat generation mechanism, a braking mechanism for detecting whether or not the vehicle is braking at the time, and a braking mechanism at the time. A battery capacity detection mechanism, a temperature determination mechanism that determines whether the vehicle needs heat or cold at that time, and a determination to evaluate those data and perform appropriate operation -It is more effective to provide a control mechanism for giving instructions.

In an electric vehicle equipped with a fuel cell, a mechanism for producing oxygen and hydrogen by electrolysis of water,
Also, by providing a mechanism for storing these oxygen and hydrogen, a high-efficiency automobile can be manufactured similarly to the above method.

In an electric vehicle that obtains driving power from a battery and a motor, it is necessary to move a cooler to lower the room temperature and to move a heater to raise the room temperature. From electricity. Also, in order to keep the battery in an appropriate temperature range, a heating mechanism and a cooling mechanism for the battery are required, and these energy sources are also electricity from the battery.

In an electric vehicle, a motor or a generator is collected during braking to generate electricity, and the battery is charged to improve the driving efficiency. However, if the generated current is too large, the entire current cannot be charged to the battery, so a part of the generated current has to be converted into heat and discarded outside the vehicle. After the battery was fully charged, all the generated electricity had to be replaced with heat and discarded outside the vehicle. Therefore, from the viewpoint of energy efficiency, a system that always keeps the charged amount of the battery at a certain level or less with respect to a full charge in consideration of the possibility of approaching a very long downhill is preferable (for example, a charging stand). When charging with, only charge up to 80% of full charge, etc.).
However, since the weight and cost of the battery required for the electric vehicle are high, it is not economical to use the battery with a margin.

[0011] By the way, as described above, electric vehicles require heat or cold, so by adding a mechanism for storing heat and a mechanism for storing cold to this system, the battery cannot be recovered and cannot be recovered as heat. Conventionally, electric energy that has been discarded can be effectively recovered. When the electric vehicle requires heat, a regenerative current is supplied to the heater to generate heat, the heat is stored, and the heat is taken out when necessary, so that the regenerative energy can be more effectively utilized. . In addition, when the electric vehicle requires cold heat, a regenerative current is supplied to a cooler to generate cold heat, the cold heat is stored, and the cold heat is taken out when necessary, thereby making the regenerative energy more effective. Can be used. According to the present invention, it is only necessary to newly add a storage portion to the generation and distribution system of heat and cold, so that more effective energy regeneration can be achieved with a slight increase in cost.

[0012] When water is used as the means for distributing heat and cold, it is highly preferable that the method according to the present invention requires only a small tank in the middle of the heat and cold distribution system.

The principle, operation and effect of the present invention in a hybrid vehicle having an internal combustion engine, a motor and a battery are basically the same as those in the above-described electric vehicle. However, since the capacity of a battery in a hybrid vehicle is considerably smaller than that of an electric vehicle, the amount of regenerative electric energy that can be effectively recovered is considerably small, and the effect of the present invention is great. However, to use an internal combustion engine together,
The merit of converting regenerated electric energy into heat and storing it is small, and it is preferable that most of the regenerated electric energy be stored as cold heat. The stored cold heat can be used particularly effectively for cooling the room in summer. Further, it can be effectively used for cooling the cooling water of the internal combustion engine (the electricity of the cooling water cooling fan can be saved). One of the features of the present invention is that it has two devices, a cold storage device and a heat storage device.

It is conceivable to store both hot and cold heat in a single heat storage device. However, if a heat exchanger is provided with a cooling function at the same time as a cooling function, this is a cooler having only a simple cooling function. The cost is higher because the mechanism is more complicated than in the case of.

As in the embodiments of the present invention described later, since the apparatus for storing hot and cold heat is separately provided, the hot and cold heat can be taken out very simply and the whole mechanism can be simplified. , Resulting in low cost.

The principle, operation, and effects of the present invention in a fuel cell vehicle equipped with a fuel cell are basically the same as those in the above-described electric vehicle. However, in a fuel cell vehicle, the capacity of the battery is considerably smaller than that of an electric vehicle or a hybrid vehicle, so that the amount of regenerative electric energy that can be effectively recovered is further reduced, and the effect of the present invention is great. However, since heat is constantly generated from the fuel cell, there is little merit in converting regenerated electric energy into heat and storing it. Most of the regenerated electric energy is preferably stored as cold heat. The stored cold heat can be used particularly effectively for cooling the room in summer. Further, it can be effectively used for cooling the cooling water of the fuel cell (the electricity of the cooling fan of the cooling water can be saved).

In a fuel cell vehicle equipped with a fuel cell, it is also effective to store regenerative electric energy during braking in the form of hydrogen and oxygen instead of cold heat. Water is electrolyzed by regenerative electric energy to generate hydrogen and oxygen, and the hydrogen is sent to a line that supplies hydrogen as fuel, and oxygen is mixed with air supplied to the fuel cell to provide kinetic energy during braking. Can be effectively collected.

[0018]

Embodiments of the present invention will be described below.

Embodiment 1 FIG. 1 is a schematic diagram showing a configuration around a temperature control system of an electric vehicle having a heat storage mechanism and a cold storage heat mechanism according to the present invention.

In FIG. 1, the driving force of the electric vehicle is generated by a motor / generator 3, and the driving force is transmitted to driving wheels 1. During acceleration and steady running of the vehicle, the motor / generator 3 is supplied with electric power from the battery 9 through the current / voltage control mechanism 4 to generate power. During braking of the vehicle, the motor / generator 3 works as a generator to convert the kinetic energy of the vehicle into electric energy, and the power is charged to the battery through the current / voltage control mechanism 4. At this time, if the current generated by the motor / generator 3 exceeds the capacity of the battery 9, the cooler 10 is operated with the excess current to generate cold heat, and the cold heat is stored in the cold storage device 11. Alternatively, the heater 13 is operated with the excess current to generate heat, and the heat is stored in the heat storage device 14.

When the cooling energy stored in the regenerative heat storage device 11 requires indoor cooling, it is mainly used for the indoor cooling and cooling radiator 1.
2 can be used effectively, and can also be used in a battery cooling / cooling heater 7 for controlling the temperature of the battery.
The heat stored in the heat storage device 14 is effectively used mainly by the room heating radiator 15 when room heating is required, and can also be used by the battery heating radiator 8 for controlling the temperature of the battery. . Fans 5 and 6 are attached to the battery cooling radiator 7 and battery heating radiator 8, respectively, and the temperature of the battery 9 is controlled to an appropriate range by sending cool air or hot air to the battery 9. I do.

An electric vehicle according to the present invention was manufactured using a lead-acid battery having a capacity of 20 kWh and a maximum output of 60 kW as the battery 9. In early August, 10 vehicle tests were performed in a mountainous area using indoor air conditioning, and the average running distance per charge was 147 km. In early February, 10 tests were conducted on a mountainous area using indoor heating with indoor heating. The average mileage per charge was 131 km.
Met.

Comparative Example 1 The regenerative heat storage device 11 and the regenerative heat storage device 14 were removed from the electric vehicle manufactured in Example 1,
The same running test as in Example 1 was performed. In early August, the vehicle was run in a mountainous area ten times with indoor air conditioning, and the average running distance per charge was 132 km. In early February, the vehicle was run 10 times in a mountainous area with indoor heating, and as a result, the average running distance per charge was 110 km.

From Example 1 and Comparative Example 1, it can be seen that the traveling distance of the electric vehicle according to the present invention is increased by 10 to 15%.

[Embodiment 2] FIG. 2 is a schematic diagram showing a configuration around a temperature control system of a hybrid vehicle having an internal combustion engine, a motor and a battery, provided with a heat storage mechanism and a cold storage heat mechanism according to the present invention.

In FIG. 2, the driving force of the hybrid vehicle is generated by an engine 17 and a motor / generator 3, and the driving force is transmitted by a transmission 16 also serving as a driving force synthesizing device.
To the drive wheels 1 through In the hybrid vehicle manufactured in this example, the engine 17 and the motor / generator 3 were arranged in parallel. The engine 17 maintains a constant output as much as possible, and controls the motor so that the fluctuation of the driving force required for traveling is carried by the motor. Electric power from the battery 9 is supplied through the current / voltage control mechanism 4, and power is generated by the motor / generator 3. When braking the vehicle, the motor / generator 3 functions as a generator to convert the kinetic energy of the vehicle into electric energy, and the electric power is charged to the battery 9 through the current / voltage control mechanism 4. At this time, if the current generated by the motor / generator 3 exceeds the capacity of the battery 9, the cooler 10 is operated with the excess current to generate cold heat, and the cold heat is stored in the cold storage device 11. I do.

When the cooling energy stored in the regenerative heat storage device 11 requires indoor cooling, it is mainly used for the indoor cooling / cooling radiator 1.
2 can be used effectively, and can also be used in a battery cooling / cooling heater 7 for controlling the temperature of the battery.
When indoor cooling is not required, the cold storage heat device 1
The cold stored in 1 can be used to cool the cooling water for cooling the engine. In a normal hybrid vehicle, the cooling water of the engine is cooled by a radiator 19 and a fan 18. In the present invention, the cold storage heat device 11 is arranged in the middle of the cooling water system.

An electric vehicle according to the present invention was manufactured using a lead-acid battery having a capacity of 3 kWh and a maximum output of 30 kW as the battery 9. Assuming that the onboard gasoline is 10 liters,
In early August, 10 vehicle tests were performed in a mountainous area using indoor air-conditioning, and the average running distance was 20 times.
It was 3 km. In early February, the vehicle was tested on a mountainous area 10 times with indoor heating in use. As a result, the average of the mileage per run was 205 km.

[Comparative Example 2] A running test similar to that of Example 2 was performed by removing the regenerative heat storage device 11 from the electric vehicle manufactured in Example 2. Assuming 10 liters of on-board gasoline and using the indoor air conditioner in early August, the vehicle was run 10 times in a mountainous area, and the average running distance was 170 km. In early February, the vehicle was tested on a mountainous area 10 times with indoor heating, and the average running distance was 197 km. Example 2 and Comparative Example 2
Thus, the electric vehicle according to the present invention has a mileage of 4 to 19
% Increase.

(Example 1) FIG. 3 is a schematic diagram showing a system configuration of a fuel cell vehicle equipped with a fuel cell and having an oxygen storage tank and a hydrogen storage tank according to a reference example of the present invention.

In FIG. 3, the driving force of the fuel cell vehicle is generated by a motor / generator 3, and the driving force is transmitted to the driving wheels 1 through a transmission 16. Electric power is generated by a polymer electrolyte fuel cell (PEFC) 21, and electric power is supplied to a motor / generator 3 through a current / voltage control mechanism 4 to generate motive power. The power generated by the PEFC 21 is also charged in the battery 9 through the current / voltage control mechanism 4. In this reference example, the capacity of the battery is 200 W
h, the power supplied to the motor is all PEFC21
However, it is possible to use a hybrid system by increasing the capacity of the battery. In the present reference example, the battery is basically used as a power source at the time of starting, and has a function of assisting in the case of short-time acceleration.

The PEFC 21 is supplied with hydrogen from the hydrogen cylinder 23 and air taken in from outside the vehicle from the air intake air 22 to generate power. Part of the air entering the PEFC 21 from the air intake device 22 is used for power generation, receives a large amount of moisture from the PEFC, passes through the steam separator 25, and is discharged outside the vehicle. The water separated by the steam separator 25 is sent to a cooling water system and stored in a cooling water tank 26. In this reference example, a hydrogen cylinder is used after being filled with pure hydrogen. The hydrogen gas exiting the hydrogen cylinder 23 is partially used for power generation by the PEFC 21 and then pressurized by the compressor and returned to the hydrogen supply line again. When power is generated by the PEFC 21, heat is generated, so the PEFC 21 must be cooled to an appropriate temperature with cooling water. The cooling water pressurized by the pump 27
After cooling PEFC21, radiator 1 if necessary
9 and the fan 18.

When the fuel cell vehicle is braked, the motor / generator 3 is operated as a generator to generate electric power, and this electric power is supplied to the water electrolysis device 31 connected to the cooling water system. The water electrolysis device 30 performs electrolysis of water to generate oxygen and hydrogen. This oxygen is stored in the oxygen storage tank 31 and supplied to the air line as required. Since the output of the PEFC 21 increases as the oxygen concentration in the air increases, it is more preferable to supply oxygen during acceleration of the fuel cell vehicle. The hydrogen generated by the water electrolyzer 30 is stored in a hydrogen storage tank 32 and supplied to a hydrogen line as needed.

The maximum output of PEFC21 was set to 50 kW, and the installed hydrogen was set to 2500 mol. In early August, 10 actual vehicle running tests were performed in a mountainous area using indoor cooling, and as a result, the average running distance for each run was 142 km. Met. In early February, the vehicle was run 10 times in a mountainous area using indoor heating, and as a result, the average of the mileage per run was 137 km. (Reference Example 2) From the fuel cell vehicle manufactured in Reference Example 1,
The same running test as in Example 3 was performed by removing the water electrolysis device 30, the oxygen storage tank 31, and the hydrogen storage tank 32. Assuming that the installed hydrogen is 2500 mol, the vehicle was tested 10 times in a mountainous area in early August using indoor air-conditioning, and as a result, the average of the mileage per run was 113 km. In early February, the vehicle was tested in mountainous areas 10 times with indoor heating, and the average running distance was 107 km.

Comparing Reference Example 1 with Reference Example 2, it can be seen that the running distance of the fuel cell vehicle increases by 26 to 28%.

[0036]

According to the present invention, it is possible to obtain an electric vehicle, a hybrid vehicle, and a fuel cell which are efficient and have a long running distance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram around a temperature control system of an electric vehicle including a heat storage mechanism and a cold storage heat mechanism according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram around a temperature control system of a hybrid vehicle including a heat storage mechanism and a cool storage heat mechanism according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a fuel cell vehicle equipped with a fuel cell equipped with an oxygen storage tank and a hydrogen storage tank according to a reference example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive wheel, 2 ... Mechanical brake, 3 ... Motor / generator, 4 ... Current / voltage control mechanism, 5, 6, 18 ... Fan,
7: Cooling radiator for electric cooling, 8: Heat radiator for battery heating, 9 ...
Battery, 10 ... cooler, 11 ... regenerator, 12
... indoor cooling air cooler, 13 ... heater, 14 ... heat storage device, 15 ... indoor heating radiator, 16 ... transmission, 17 ... engine, 19 ... radiator, 21 ... polymer electrolyte fuel cell (PEFC), 22 ... air suction device, 23 ... hydrogen cylinder, 24 ... compressor, 25 ... steam-water separator, 26
... cooling water tank, 27 ... pump, 30 ... water electrolyzer, 31 ... oxygen storage tank, 32 ... hydrogen storage tank.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60T 1/10 B60T 1/10 H02J 7/00 H02J 7/00 P (72) Inventor Takeshi Yamaga Hitachi, Ibaraki 7-1-1, Omika-cho, Hitachi City Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Yuichi Kamo 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi, Ltd. (Reference) 5G003 AA07 BA01 CA01 CA11 CC02 DA07 DA17 FA08 5H115 PA11 PG04 PI11 PI16 PI18 PI29 PI30 PO17 PU01 PU23 PU25 QA02 QA04 QI04 SE04 SE06 UI29

Claims (6)

[Claims] An automobile which obtains all or a part of a driving force by using electric energy, is provided with both a heat storage mechanism and a cold storage heat mechanism. 2. An electric vehicle which obtains power by operating a motor using electric energy stored in a battery, wherein the electric vehicle has both a heat storage mechanism and a cold storage heat mechanism. 3. An automobile having a hybrid mechanism including an internal combustion engine, a motor and a battery, wherein the automobile has a regenerative heat storage mechanism. 4. An automobile comprising a fuel cell, a battery and a motor, wherein the automobile is provided with a cold storage mechanism. 5. An automobile according to claim 1, wherein said heat storage mechanism and said cold heat storage mechanism store heat or cool heat in water. 6. A vehicle for obtaining all or a part of a driving force by using electric energy, a braking detection unit for detecting the presence / absence of braking, and whether the whole vehicle needs heat or cold at that time. A temperature determination mechanism for determining whether it is necessary, a heat conversion mechanism for converting kinetic energy during braking to heat, a cold heat conversion mechanism for converting kinetic energy during braking to cold heat, and a heat storage mechanism for storing the heat And a cold storage mechanism for storing the cold heat, and a control mechanism for controlling the cold storage mechanism.