HYBRID CAR – NEED OF DAY

                                                              ABSTRACT

            In this paper, a unique technology of HYBRID CAR is discussed which has high efficiency and hence is environment-friendly.

            In daily routine we come across different types of cars which are large in number. These are not called hybrid cars because they are running by single source of energy which may be petrol or diesel. In HYBRID CAR, two energy sources are used one is petrol / diesel / gas and another one is electric batteries. These two sources are stimulated by a unique device called as “Power Split Device” which is responsible for maximization of fuel economy.

            All plus points of these both sources are accumulated to get maximum efficiency which is nearly double than the other cars and tail-pipe emission is reduced by 90% approximately.

            These cars have unique place in automobile market because drawbacks of insufficient sunlight (in monsoon days) in case of solar car and frequent recharging of batteries in electrical cars (like REVA) are solved in this model.

1. INTRODUCTION

            Automobiles are inseparable part of our daily routine which consume fuel. This fuel is also a big question before human being as it is limited in stock. It also causes pollution which is responsible for drastic changes in biological clock.

            Hence, some research works are in process to make car run on non-conventional energy sources like sunlight. But yet, man has not succeeded to replace present technology.

            Hybrid cars use both electric batteries and fossil fuels for its working simultaneously which leads to somewhat complex technology where it makes use of advanced electronic and electrical circuit.

            TOYOTA has brought a practical solution in the form of “TOYOTA PRIUS” which can solve problem to some extent and alleviate pollution.

2. WHY SUCH COMPLEX TECHNOLOGY IS REQUIRED?

            Now a day advanced cars are available which are capable to accelerate to 100kmph within few seconds. Such cars are full of luxury but fuel efficiency is very low, more over they create pollution also.

            Now such situation is prevailing that fuel economy has to be maximized and pollution has to be minimized. In case of conventional cars, fuel economy is less and contribution to pollution is large. Some research works are going on to make car run on solar energy and electrical batteries but in this case one has to compromise over luxuries provided by other cars. Hence some unique technology is required which will give higher fuel economy, less pollution and no compromise over luxuries.

3. ENGINE STRUCTURE

            Two different types of structures are available in hybrid car technology.

One is parallel technology and the other is series technology.

Fig 3 . 1

In parallel structure, there is fuel tank to supply petrol but it also has set of batteries to supply power to electrical motors. Here, both sources are used for transmission at same time.

In series, petrol engine turns a generator, which either can charge batteries or provide power to the electric motor that performs the transmission.

 Fig.  3 . 2

4. ENGINE COMPONENTS

Various components used in this HYBRID CAR are as follows:-

4.1  HYBRID SYSTEM

It is a complex technology that runs on electricity at lower speeds when the engine is less efficient and switches to petrol only after it picks up speed.

4.2  BEAMS 

(BREAK through ENGINE with ADVANCED MECHANISM SYSTEM)

BEAMS powers hybrids system. It is highly efficient system that is     INZ-FXE-1500cc, 58bhp, four cylinders and petrol unit with VVT-T. The engine on a hybrid car will be smaller and will use advanced technologies to reduce emissions and increase efficiency.

4.3  MOTOR GENERATOR

This electric motor is very sophisticated. Advanced electrical technology allows it to act as motor as well as generator.

4.4  METAL HYDRIDE BATTERIES

These batteries are similar to those in conventional flashlights. They are placed behind the rear seat. They last for about 2,40,000 km before they need replacement and never have to stop for recharge.

4.5  FUEL TANK

The fuel tank in a hybrid car is the energy storage device for the petrol engine. Petrol has a much higher energy density than batteries do.

5. HOW TECHNOLOGY WORKS?

Petrol and electric cars have two things to be noticed:

·         Petrol engine gives optimum performance with minimum tail-pipe emission at moderate engine speed only, and

·         In electric car tail-pipe emission is zero as it runs on batteries but its speed range is very low.

This technology works on a HYBRID SYSTEM that is in communication with both petrol engine and batteries, and consists of generator, electric motor as transmission system.

6. WHAT MAKES SYSTEM EFFICIENT?

The efficiency of the hybrid technology depends on following factors:-

6.1 DIFFERENT SPEED RANGES

6.1.1 Speed range: - 0 kmph

This speed range indicates that a vehicle is just started. Petrol engine is used to start the car propulsion system, after several seconds, the engine warms up all the car system. The petrol engine shuts off, there by minimizing tail-pipe emission.

6.1.2 Speed range: - 0 – 20 kmph

At this speed range, petrol engine is completely shut off and the drive is powered by batteries at slow speed. Thus at this speed range, tail-pipe emission is zero.

If we compare the same speed range of petrol engine, we can see that the tail-pipe emissions are maximum as specific fuel consumption is high.

6.1.3 Speed range: - 20-60 kmph (moderate speed)

At moderate speed, the petrol engine takes over the charge and car runs only on petrol propulsion system. But again, tail pipe emissions are minimum as the engine is running at a speed of about 3000 to 3500 rpm.

6.1.4 Speed range: - Above 60 kmph

At very high speeds, additional power is required which is supplied by the electric motor, which gets it power from battery. In this case, also the petrol engine is still running at moderate speed at 3000 to 3500 rpm. And tail-pipe emission to lowest possible value.           

6.2 POWER SPLIT DEVICE

    Decision of which energy source is to be used is taken by a unique device called as power split device. This allows engine to stay in its most efficient mode and speed range most of the time.

PSD has a clever gear box that hooks the petrol engine, generator and electric motor together.

6.3 RECOVERY OF ENERGY AND STORAGE IN THE BATTERY

            Whenever breaks are applied to moving car, actually energy is removed from the brake. Faster the car is moving, the more kinetic energy it has. The brakes of a car remove this energy and dissipate it in the form of heat. A HYBRID CAR can capture some of this energy and store it in the batteries to use it later. It does this by using “regenerative braking”. Instead of just using the brake to stop the car, the electric motor that drives the hybrid can also slow the car. In this mode, the electric motor acts as a generator and charges the batteries while the car is slowing down.

7. SPECIAL FEATURES

7.1  Recharging of batteries during deceleration and braking:- The problem of recharging the batteries is completely eliminated in this system. Here batteries are charged by generator during gradual deceleration period.

7.2  At signals and short stops:- If this system has to stop at signals its exhaust emission are zero and when traffic crawls, car is powered by electric motor only. This feature is very suitable for roads in India.

7.3  Control on air fuel ratio:- In conventional fuel engine, air-fuel ratio varies according to load on it. When this is rich in percentage of fuel is more in air fuel mixture that causes higher tail pipe emission. Hence in this system air fuel ratio is kept constant.

7.4  During acceleration:- When the speed of car increase above 120 kmph the engine works in tandem with the electric motor – it kicks in like a super charger to gain optimal power with optimum fuel economy at a continuous speed.

8. ADVANTAGES OF USING HYBRID SYSTEM

8.1  Environment friendliness: - The car equipped with hybrid system emits only half the CO2 of a regular 1.5 ltr. Engine and reduces other tail pipe emissions by 90%. In this way it reduces the problem of air pollution to a large extent and protects nature

8.2  Recharging facilities of the battery:- Unlike electric car batteries are not required to be charged at regular interval as the hybrid system. It self generates the supply of kinetic energy from braking that is converted into electricity, which keeps them recharged.

8.3  Less noise: - The hybrid system uses the quite engine and electric motor which makes no noise during the operation reducing the sound pollution as well.

8.4  Optimum fuel efficiency :- This system results in the ultra efficient fuel consumption level which is nearly, twice the fuel efficiency of conventional petrol engine cars.

8.5  Economical aspects: - Initial cost of this technology is high but process of mass production will certainly reduce its initial cost to such a level that it will even beat the conventional fuel cars.

Again its working cost is nearly half than that of the conventional cost.   Thus, it will be greatly economical.

9. CONCLUSION

                        As discussed in the earlier pages, the conventional fuel cars are the main source of environmental pollution, about 60% of the air pollution is done by automobiles and they also have large contribution in sound pollution. Electric cars are invented to overcome air and sound pollution but due to some inherent limitations of electric cars (like recharging of batteries etc.) their use is limited.

                        Hybrid propulsion system may not be a complete solution to reduce pollution as it uses fuel, but the overall concept is most significant than other ones. In other words, car running on the hybrid system are most successful “ENVIRONMENT - FRIENDLY” in the world of automobiles.