Project Report On

WIND ENERGY FOR AUTOMOBILE REFRIGERATION

Submitted By:

Arpita Sethi - M-19-2K11

Deepa kumari - M-32-2K11

Jyoti Yadav - M-50-2K11

Kirti Dang – M-55-2K11

Manisha Duhan - M-63-2K11

Under the guidance of

Dr. Arvind Gupta

( Associate professor Mechanical department )

A Project Report submitted in partial fulfilment for the requirements of final year

YEAR OF SUBMISSION - 2015

(YMCA University of Science & Technology, Faridabad)

1

Declaration

We hereby declare that this submission is our own work and that, to the best of our

knowledge and belief, it contains no material previously published or written by

another person nor material which to a substantial extent has been accepted for the

award of any other degree or diploma of the university or other institute of higher

learning, except where due acknowledgment has been made in the text.

Name: Roll no: Signature

 Arpita Sethi M-19-2K11

Deepa Kumari M-32-2K11

Jyoti Yadav M-50-2K11

Manisha Duhan M-63-2K11

Date:

2

Certificate

This is to certify that our project work entitled “WIND ENERGY FOR AUTOMOBILE

REFRIGERATION ” is an authentic record of our work carried out at “YMCA University

of Science & Technology”, as per requirement for partial fulfilment of final year for the

award of degree of B.Tech. Mechanical Engineering, under the guidance of Dr. ARVIND

GUPTA.(Associate professor, mechanical department,YMCAUST).

ARPITA SETHI

DEEPA KUMARI

JYOTI YADAV

KIRTI DANG

MANISHA DUHAN

Certified that the above statement made by the students is correct to the best of my knowledge and belief

Date: April 21, 2015 Dr. ARVIND GUPTA

(Associate Professor , Mechanical department )

YMCAUST

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Acknowledgement

With profound respect and gratitude, we take the opportunity to convey our thanks to we do

extend our heartfelt thanks to Dr.Arvind Gupta (Associate professor , Mechical

department YMCA) for providing his valuable guidance and ideas for completing this final

semester project. We are extremely grateful to all the technical workshop staff of YMCAUST

for their co-operation and guidance. We have learnt a lot working under them and we will

always be indebted of them for this value addition in me. We would also like to thank the

project in charge Mr. Nikhil Dev and Mr. Atul of YMCA UST ,Faridabad and all the faculty

members of Mechanical Engineering Department for their effort of constant co operation,

which have been a significant factor in the accomplishment of our major Project.

(Jyoti yadav,

Manisha duhan,

Kirti dang ,

Arpita sethi,

Deepa kumari )

YMCAUST FARIDABAD

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Abstract

This project entitles the use of wind energy for automobile refrigeration. Wind energy can be converted into electrical energy using small wind turbines and generator . The operation, performance and efficiency of vehicles can be made very much environment friendly. This may be done by using the energy of wind which is caused by the relative motion between the vehicle and the wind surrounding it. Small Wind turbines with horizontal axis can be mounted on the body structure of the vehicle to generate electricity in such a way that it must not create any additional drag force (rather than the existing drag force due to frontal area and skin friction) upon the vehicle. An elaborate aerodynamic analysis of the structure of the vehicle along with the flow pattern and wind turbine is analysed in this report. Some techniques and methods are proposed to minimize the drag imposed by the introduction of the turbines as much as possible. Location of wind turbine is also being analysed Optimum values of different design parameters and related power produced at different rated velocity of the automobile .

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Table Of Contents

S. No. Name of Experiment Page no.

1. Declaration 2

2. Certificate 3

3. Acknowledgement 4

4. Abstract 5

5. Introduction 8-10

6. Small Wind Turbine For Automobile 11

7. Current State Of Arts 12-13

8. Frictional Drag On Moving Car 14

9. Automobile Ac 15-19

10. Literature Survey And Problem Statement 20

11. Micro Wind Turbine Aerodynamics 21

12. Wind Generator Technology 22-26

13. Equipment Details 27-30

14. Calculations 31-34

15. Advantages Of Using 2 Turbine 35

16. Conclusion 36

17. References 37

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List of Figures :

Figure no Description Page no1 Car showing position of micro wind turbine 102 Car ac cycle 173 Refrigeration cycle 184 Car ac system 195 Horizontal axis wind turbine 25

6 Various turbine positions 25

7 Ford motor model 268 Conversion of wind energy to electrical 269 Graph between power coff. Vs tip speed ratio 28

10 Charging and control circuit 30

11 Design of various radiator grills for different cars 32

12 Resultant thrust generated on wind turbine due to flowing air

35

List of Tables :

Table no Description Page no1 Power produced at different speeds in automobile 33

2 Comparison of power produced at different speeds 34

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Introduction

Wind energy for automobile refrigeration means utilization of wind energy for

partially charging of automobile air conditioning. Generally the vehicle which has air

conditioning system consume more fuel as compare to other vehicle in which there is

no any air conditioning system. As we all know the price of fuels like petrol, diesel,

CNG, etc. are increasing day by day due to this mostly people avoid to use air

conditioning during their rides. Thats why we have tried to give solution of this

problem.

For this purpose we have used micro wind turbines in vehicles. Research paper shows

that there can be different position for installed micro wind turbine in vehicles. But

according to our study the best positions are in the front parts of car that is bumper

and on rear sides of vehicles.

A micro  wind turbine is a wind turbine used for microgeneration, as opposed to large

commercial wind turbines, such as those found in wind farms, with greater individual

power output.  They are usually approximately 7 to 25 feet (2.1–7.6 m) in diameter

and produce electricity at a rate of 300 to 10,000 watts at their tested wind speed.

Some units have been designed to be very lightweight in their construction, e.g.

16 kilograms (35 lb), allowing sensitivity to minor wind movements and a rapid

response to wind gusts typically found in urban settings and easy mounting much like

a television antenna. It is claimed, and a few are certified, as being inaudible even a

few feet (about a metre) under the turbine.

Micro turbines have been gaining in popularity since 2000 due to their increased

efficiency over generators. These small electric generators burn gaseous and liquid

fuels to create high-speed rotation to turn an electric generator.

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Micro turbines range from 30 to 350 kW, while conventional gas turbine sizes range from 500 kW to 250 MW.

A report prepared for the Environmental Protection Agency says microturbines are best suited for distributed-generation applications due to their flexibility in connection methods, their ability to be stacked in parallel arrangements for larger loads, their stable and reliable power, and their low emissions

Wind power is produced by using wind generators to harness the kinetic energy of wind. It is gaining worldwide popularity as a large scale energy source, although it still only provides less than one percent of global energy consumption.

Wind power captures the natural wind in our atmosphere and converts it into mechanical energy then electricity.

People started using wind power centuries ago with windmills, which pumped water, ground grain, and did other work.

Today's wind turbine is a highly evolved version of a windmill. Modern wind turbines harness wind's kinetic energy and convert it into electricity.

Most wind turbines have three blades and sit atop a steel tubular tower, and they range in size from 80-foot-tall turbines that can power a single home to utility-scale turbines that are over 260 feet tall and power hundreds of homes.

Wind is a type of renewable energy, and there are three major types of wind power.

The major types of wind power are:

Utility-scale wind: wind turbines larger than 100 kilowatts are developed with electricity delivered to the power grid and distributed to the end user by electric utilities or power system operators;

Distributed or "small" wind: which uses turbines of 100 kilowatts or smaller to directly power a home, farm or small business as it primary use.

Offshore wind:which are wind turbines erected in bodies of water around the world, but not yet in the United States.

Wind power has increased exponentially since the dawn of the 21st century. The adoption of wind energy globally has changed dramatically since the 1980's when California was home to 90% of the world's installed wind energy capacity. In fact, the amount of operating wind energy capacity has increase more than 16 times between 2000 and 2012, to over 282,000 MW of operating wind capacity.

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Different Components shown in figure:

AC Pulley (CB) Circuit Breaker (DM) Drive Motor (BP) Battery Pack (SS) Start Switch (D)Drive Motor (G) Generator (WT) Wind Turbine (WH) Wire Harness (ST) Spare Tire.

Fig1: car showing position of microwind turbine

Fig source : wikipedia

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Small Wind Turbines For Automobiles

It is assumed that the vehicle is moving in a calm and steady wind stream with zero

wind velocity. If the vehicle is moving at a constant speed of 15 m/s (54 km/h), then

we can think a wind stream with15 m/s is flowing around the vehicle. Normally this

wind will cause a drag force which is opposite to the direction of the propulsion of the

vehicle. At constant speed (zero acceleration) the energy requirements to move the

vehicle forward are –To overcome the frictional force (rolling resistance of road) and

to overcome wind resistance . At this Condition, if the air stream flowing around the

vehicle (which was not interacting with the vehicle previously) is allowed to enter

inside and let it flow down to the rear side; then it may be possible to use these air

streams to generate power. The vehicle has already interacted with this wind and it

deflects the stream of wind at the two sides of it by stagnation at the front. This is the

energy that had been lost from the vehicle to overcome the aerodynamic resistant.

Now if these stream generated by the interaction of the wind and vehicle is captured

within the vehicle in such a way that it would not impose an additional drag at the

direction of propulsion of the vehicle, some of the energy can be recovered and fed

back to the battery by means of conventional energy conversion processes. Placing a

wind turbine can serve the purpose. At the same time it will help to increase the

pressure at the back side (according to Bernoulii’s equation pressure will be increased

if velocity is decreased and velocity will be reduced at the back side of the turbine

after energy extraction) which will reduce the drag force that existed before with the

conventional design of the vehicle. So, vortex shedding will be reduced at the rear

side. For this it is necessary to modify the design of a vehicle which gives provision

of air flow through the vehicle. On the other hand positioning of the turbines will also

be important because they must be placed in such a way that they do not impose or

create any additional drag on the vehicle. Symmetrical positioning of the turbine can

do the trick as the thrust acting on the turbines will cancel each other.

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Current State Of The Art

The micro wind turbine market has exploded in the last three years – heck, even the

National Football League is on board with wind power – so now is a good time to update

one of CleanTechnica’s most popular posts from 2008, “Top Five Micro Wind

Turbines.” With three of 2008’s top five micro wind turbines coming from one company, we

thought it was time to branch out a bit and give you a more expansive picture of the potentials

for micro wind power in 2012 and beyond. Just one caveat: this article is not endorsing any

particular company or wind turbine, but at the end you’ll find some tips on researching the

product that’s right for you.

We’re featuring Southwest Windpower’s popular Skystream 3.7 turbine  in this year’s top

five not only because it continues to get good reviews, but also because last month the

company announced that it is one of three wind turbines qualifying for California’s wind

energy rebate, under strict new guidelines that include third-party certifications and 

performance verification. Southwest Windpower estimates that the rebate for a Skystream

comes to $6,750 based on the California Energy Commission’s rebate of $3.00 per watt of

rated capacity. The Skystream 3.7 comes with a five-year warranty and a software package

that enables you to monitor it from your computer. It is also now available in a wind-solar

hybrid package, so if you’re interested in this product be sure to research it from both the

wind and solar angles.

An other company news, earlier this year SouthWest Wind partnered with GE to develop

what they bill as the first fully smart grid-enabled micro wind turbine for residential use,

the Skystream 600.

How to know about this technology

 A group of Delhi University students has discovered an innovative way of harnessing wind

energy churned out by Metro trains to generate electricity. They  proposed setting up a

turbine at an underground metro station to check if it can be successful in harnessing the wind

energy.

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Without obstructing the operation, safety and security of Metro services, it was decided to put

up turbine along the underground tracks at the mouth of tunnel where the maximum wind

velocity available is 6.5 m/s

In the first phase, they installed a three-blade turbine and later a five-blade light rotor turbine

with a cut-in speed of less than 1.5m/s. they connected it to a battery and measured the power

it generates

After listened this news me and my group member truly inspired by this technology.

Fortunately an idea come in our mind , why should we not use this technology in cars .

Some warm up to micro wind turbine

Small wind turbines generate less than 100 kilowatts, and installation can be costly and time-

consuming. But an increasing number of rural property owners are nevertheless buying them

to provide backup power.

Xzeres, a Wilsonville company, manufactures two types of horizontal turbines: a 2.5-kilowatt

system and a larger, 10-kilowatt system. The firm has sold 150 systems since beginning to

sell them earlier this year. Nationwide, U.S. manufacturers sold $82.4 million worth of new

systems for 2009, a 15 percent increase over 2008, according to the American Wind Energy

Association

The popularity of small wind turbines could be greater, but permitting is a significant

drawback, said Qua Le, vice president of sales and business development for Xzeres, a

Wilsonville company that manufactures small wind turbines. While the small wind system

itself may cost only $6,500, permitting and installation can increase project costs to $12,000

to $17,000. After a harsh winter in Central Oregon last year, Evergreen Energy of Bend got

a call from a woman who wanted to install a small wind turbine and a backup propane

generator on her property. She lost power for five days over the winter, and did not want to

depend on the grid for another year, according to Mark Patt, owner of Evergreen Energy.

Such calls are becoming more frequent, Patt said, though people sometimes need a year to

become convinced that the systems are worth the money.

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Frictional Drag On A Moving Car

When a vehicle moves it experience wind resistance which are classified in two different

forms- frictional drag and form drag.Frictional drag arises due to viscosity of air and form

drag arises due to variation of air pressure in the front and rear side of the vehicle . As the

vehicle moves forward, it lefts the air stream behind. A turbulence or disturbance is created

on the wind when a vehicle moves through it. If stationary wind turbines are placed near the

road then energy can be extracted from the wind stream generated due to the movement of

the vehicle. Such a study had been carried out in University of Arizona by a group of

students. If it is possible to capture those wind streams within the vehicle itself then it can be

used to recover some of energy that has been used to overcome the form drag (aerodynamic

drag) of the vehicle. If this wind energy is used to extract some power in such a way that it

does not create any component of force or thrust opposite to the direction of the propulsion of

the vehicle, then this gained energy can be used to produce electricity to charge up the battery

of the electric vehicle itself. At the same time drag can be expected to be reduced by passing

this air to the rear side (Low pressure side) of the vehicle. Air stream sliding over the body of

the vehicle cannot enter into the rear side due to vortex shedding . If air streams are allowed

to flow in this region by any means then the form drag will be reduced by some amount and

at the same time it may be possible to generate electricity using the kinetic energy of wind.

Several studies had been carried out in this field but none of them are proved to be scientific.

During the Second World War, wind turbines are used in submarines to charge up the

batteries when they remained static and float in the water. At present it is also common to use

turbines in ships, caravans and vehicles when they are parked.

Electrical energy produced by a wind turbine has many uses. Converting wind energy into

electric energy enables the user to store energy in a battery, transmit it over long distances, or

convert the energy into many different forms (mechanical energy, heat, etc.). Most of the

large wind turbines are connected to the grid. In some small applications, wind turbines are

operated in isolated operation . Battery charging is very popular because of its simplicity and

versatility. DC or AC generators can be used

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Automobile Air Conditiong

Automobile air conditioning (also called A/C) systems cool the occupants of a vehicle

in hot weather.Automobile air conditioning systems cool the occupants of a vehicle in hot

weather, and have come into wide use from the late twentieth century. Air conditioners

use significant power; on the other hand the drag of a car with closed windows is less

than if the windows are open to cool the occupants evaporatively.There has been much

debate on the effect of air conditioning on the fuel efficiency of a vehicle.

Factors such as wind resistance, aerodynamics and engine power and weight have to be

factored into finding the true variance between using the air conditioning system and not

using it when estimating the actual fuel mileage. Other factors on the impact on the

engine and an overall engine heat increase can have an impact on the cooling Air

conditioning like it says 'conditions' the air. It not only cools it down, but also reduces the

moisture content, or humidity. All air conditioners work the same way whether they are

installed in a building, or in a car. The fridge or freezer is in a way an air conditioner as

well.

Air conditioning is a field in it's own right, but we'll stick to the main points or a car's air

conditioning and the main parts used and a few hints to keep the air-con system running

properly.A number of people don't realise that turning on the air conditioning actually

reduces the number of miles per gallon of your car. There is energy used in removing the

heat and moisture from the air in the car, and this consumes petrol because of the extra

engine load.Air conditioning's main principles are Evaporation and Condensation, then

Compression and Expansion.

Hard tubing and flexible hoses connect all the actual components of the air conditioning

in your car. Evaporation and condensation, expansion and compression are the physics of

why it works.

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There are five main components to the whole system, namely the Compressor, Condenser, ,

Receiver-dryer, Expansion valve, and the Evaporator.

 

The fluid that passes around the whole system is the refrigerant. The refrigerant can

evaporate at a low temperature, and then condense again at a higher pressure. In the bad old

days, R-12 was the refrigerant used in almost all cars. It was widely available, however it was

found to be a contributor to the hole in the earth's ozone layer as it was a chlorofluorocarbon

(CFC). These refrigerants were discontinued, and all cars after 1996 use a non-CFC fluid

called R-134A which is kinder to the environment.

So, here is how all the various parts of a car's air conditioning works:

Compressor: The compressor is the work horse of the air conditioning system,  powered by a

drive belt connected to the crankshaft of the engine. When the aircon system is turned on, the

compressor pumps refrigerant vapour under high pressure to the condenser.

Condenser: The condenser is a device used to change the high-pressure refrigerant vapor to a

liquid. It is mounted in front of the engine's radiator, and it looks very similar to a radiator.

The vapour is condensed to a liquid because of the high pressure that is driving it in, and this

generates a great deal of heat. The heat is then in turn removed from the condenser by air

flowing through the condenser on the outside

Receiver: The now liquid refrigerant moves to the receiver-dryer. This is a small reservoir

vessel for the liquid refrigerant, and removes any moisture that may have leaked into the

refrigerant. Moisture in the system causes havoc, with ice crystals causing blockages and

mechanical damage.

Expansion Valve: The pressurised refrigerant flows from the receiver-drier to the expansion

valve. The valve removes pressure from the liquid refrigerant so that it can expand and

become refrigerant vapour in the evaporator.

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Evaporator: The evaporator is another device that looks similar to a car radiator. It has tubes and fins and is usually mounted inside the passenger compartment behind the fascia above the footwell. As the cold low-pressure refrigerant is passed into the evaporator, it vaporises and absorbs heat from the air in the passenger compartment. The blower fan inside the passenger compartment pushes air over the outside of the evaporator, so cold air is circulated inside the car. On the 'air-side' of the evaporator, the moisture in the air is reduced, and the 'condensate' is collected and drained away.

Compressor: The compressor then draws in the low-pressure refrigerant vapour to start another refrigeration cycle. The refrigeration cycle then runs continuously, and is regulated by the setting of the expansion valve.

Fig2:car ac cycle

Fig source: Wikipedia images

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Fig 3: Refrigeration cycle

Fig source:

18

Fig 4: car ac system

Fig source:freefilehunt.com

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Literature Survey And Problem Statement

As energy demand continues to grow in sync with economic growth, and costs of impending

climate change become internalized through regulation, wind energy will have increasing

prevalence in the global energy mix. Regulatory influence, including renewable portfolio

standards, tax incentive programs, and possible carbon credit legislation, along with declining

fossil fuel reserves are driving the shift. The US Energy Information Administration projects

electricity demand to increase 39% from 2005 to 2030, and the Department of Energy has an

overarching proposal to increase wind energy's fraction of this US electricity supply to 20%

in 2030.

Currently, wind power is largely produced through horizontal-axis, land-based and offshore

turbines. This technology is relatively mature, and as of 2011, NREL reports that the US

currently has about 44 GW of wind turbines installed. To get to 20% in 2030, approximately

300 GW of installed wind power will be needed. Current technology, however, has several

limitations. Namely, wind resource near the ground is often inconsistent and low-speed. This

results in a low capacity factor, which represents the actual power produced in a given time

period divided by the theoretical rated maximum for the turbine. The highest wind speeds are

at much higher elevations than practical to reach for land-based turbines, and these winds are

what airborne wind power devices hope to access.

Incremental innovations are continually occurring to decrease capital costs and increase

performance, but the prospect of airborne wind power represents a true disruptive change.

Airborne wind devices use much less material for a specific rated power output than land

turbines. Also, they have a higher capacity factor, making them more suitable for utility scale

grid integration. In this survey, I will touch on the basics of wind resource availability and

highlight some of the major designs proposed to extract this high-altitude wind energy.

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Micro Wind Turbine Aerodynamics

The shape and dimensions of the blades of the micro wind turbine are determined by the

aerodynamic performance required to efficiently extract energy from the wind, and by the

strength required to resist the forces on the blade.

The aerodynamics of a horizontal-axis microwind turbine are not straightforward. The air

flow at the blades is not the same as the airflow far away from the turbine. The very nature of

the way in which energy is extracted from the air also causes air to be deflected by the

turbine. In addition the aerodynamics of a wind turbine at the rotor surface exhibit

phenomena that are rarely seen in other aerodynamic fields.

In 1919 the physicist Albert Betz showed that for a hypothetical ideal wind-energy extraction

machine, the fundamental laws of conservation of mass and energy allowed no more than

16/27 (59.3%) of the kinetic energy of the wind to be captured. This Betz' law limit can be

approached by modern turbine designs which may reach 70 to 80% of this theoretical limit.

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Wind Generator Technology

The wind system comprises; the generator, blades, and tail vane mechanism, tower, charge controller and batteries.

Each component is described briefly below:-

The Permanent Magnet Generator (PMG) : The magnet rotor disks are mounted on a bearing hub so they can rotate on the shaft. They are directly driven by the blades of the wind generator. Almost every small wind generator on the market uses a directly driven permanent magnet generator (PMG) of some similar type. They are specially designed and built for the purpose of extracting power from the slowly turning blades with best efficiency and minimum complexity. Between the rotors is a stator, cast from plastic resin, holding coils of copper wire.(Most other PMGs use a laminated steel core for the stator instead.) The ITDG PMG is constructed as far as possible using readily available materials and off the-shelf components.

Electricity is generated when the magnets on the magnet disks rotate past the coils embedded in the stator casting. The magnetic field induces a voltage in the coils which is ultimately fed to the batteries. At low rotational speeds the voltage is insufficient to charge the battery, but when “cut-in” wind speed is reached, a current flows into the battery so as to charge it.

The magnetic field through the coils reverses as the magnet poles in the rotor disks pass them, so the voltage produced alternates also, which means that the generator produces alternating current, or AC.

The coils are arranged “three-phase” to make most efficient use of the space available, and deliver a smooth output. The three-phase AC is converted into direct current, or DC, so that it can charge the battery. The device which converts AC to DC is called a rectifier.

The blades :Modern wind turbine rotors usually have two or three blades. A larger number of blades would create more turning force (torque), but would not be capable of driving the PMG fast enough to generate the required voltage, because it would turn more slowly. The higher speed rotor actually catches slightly more power than the slow one would. The rotor blades and the PMG are both very carefully designed to match each other’s speed and power, so as to extract the maximum energy from the wind. The output of the wind generator over time depends more on the amount of wind swept by the blades than it does on the power rating of the PMG.

Electricity generation is especially valuable during low wind periods, when the battery

otherwise becomes discharged. At low speeds power output depends only on the area of wind

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swept by the blades. The rated power output only occurs in stronger winds, so it is not seen

under these conditions. If the PMG is not connected to a battery or other

electrical load, then the blades will over speed, like an engine at full throttle, out of gear. The

machine will become noisy and may vibrate so much that parts come loose and fall to the

ground.

To prevent this type of problem the following things are important:

Keep the wind generator connected to a load at all times.

The wind generator must have an effective furling system for high winds.

The blades should be carefully balanced so they run smoothly.

Tail vane mechanism: The tail vane is used to face the machine into the wind. It also

includes a mechanism which comes into play when wind speed exceeds a certain level

(usually around 10 metres per second). It ‘furls’ the generator and blades out of the full force

of the wind, by swivelling the whole machine on a bearing (the yaw bearing) at the top of the

tower. A simple mechanism using gravity on the tail vane maintains the generator and blades

facing the wind when the wind is moderate, but turns it sideways-on in very strong winds.

This system is essential to protect the blades from overspeed and the PMG from damage

Tower :The tower raises the generator, blades and tail vane to a height where the wind is

stronger and smoother than at ground level. The tower is as high as possible above all

surrounding obstacles. Trees and buildings will affect the wind to a height almost double

their own height, but practical considerations, such asexpense, safety and maintenance limit

the height to between 10m and 20m

Electrical controls

Charge controller:The charge controller is there to prevent damage to the batteries. If the

batteries are near to full charge, but the wind is blowing strongly, the charging current needs

to be reduced to prevent damage to the battery. The charge controller will divert some power

from the generator away from the battery and into a ‘dump load’. This can be anything from a

series of bulbs to a heating coil – in the simplest systems this excess energy is wasted. Charge

23

controllers for solar PV systems are not suitable for wind generators because they unload the

wind turbine by disconnecting it from the battery. Different types of battery require different

settings in the charge controller. For example, sealed batteries are charged at a lower voltage

to prevent gassing, whereas vented batteries are allowed to charge more vigorously and

produce gases .

Low voltage disconnect: Batteries are easily damaged by excessive discharge. A device that

cuts off the current from the battery to the user load (light and other circuits) at a pre-set low

voltage can prevent this. Such a device is often called a 'low voltage disconnect'. This sort of

device is recommended where users will attempt to use energy from the battery until it runs

out. With education and user vigilance such devices are unnecessary.

Inverter: Inverters are used to convert the low voltage DC from the battery (usually12V) into

mains type 230/240V AC. Higher output-quality inverters are better for most purposes, but

these can add substantially to the cost of the whole system. Lower cost inverters have lower

output, and/or12

lower protection against abuse. Inverters generally make sense for small

networks of households with a central generator, since the additional cost can be shared, and

the cable runs are long enough to require the higher voltage supply.

Load control: In more sophisticated systems, and especially where there is more than one

household using the batteries, an individual load, or a group of loads, can be individually

controlled to match demand and supply. These different loads will be switched on and off

depending on the state of the battery charge and this can be done randomly or sequentially.

Batteries: For stand-alone wind systems, where a constant supply of electricity is desirable, it

is essential to have a battery to store electricity for when the wind is light. The battery also

regulates the voltage of the system, which would otherwise vary wildly with wind speed and

cause damage to equipment.

Fuses and circuit breakers :Over current protection is as important in small wind systems as

in households on the grid. Fuses and breakers prevent too much current from flowing in

circuits or appliances, causing damage or fire through faulty wiring. A battery can deliver

very high currents under short-circuit conditions, so fuses or circuit breakers are highly

recommended for fire safety.

24

Fig 5:horizontal axis wind turbine

Fig source:freepix.eu

Fig 6:various turbine positions

Fig source: Wikipedia images

25

Ford motor company is an American automaker and the world's fifth largest automaker based on worldwide vehicle sales. It is in process of making cars installed with micro wind turbines to effectively utilize wind energy for automobile refrigeration. Their proposed design have micro wind turbines installed on roof of car and the following figure shows this model

Fig 7: ford motor model

Fig source:Wikipedia images

Fig 8:conversion of wind energy to electrical

Fig source :Wikipedia images

26

Equipment Details

Wind turbine

The wind turbine chosen for power generation has the features stated bellow –

Two blades (for low solidity).

Horizontal axis.

Lift type.

High lift to drag ratio with efficiency ranging from 0.4 to 0.45. They need a relatively high

tip speed ratio (λ = ωR / vw). For our design we have chosen λ = 6. For this value of λ it can

be assumed that the value of C Fwill be 0.4 to 0.45.

Where,

CF = axial thrust co-efficient.

So, Cp/CF ≈ 7

This implies that as at perfect dynamic matching generated power will be greater than the

power spend due to thrust. In other words the generated power by a turbine will be greater.

than the thrust acting on the blade as an aerofoil section has high lift to drag ratio. On the

other hand, turbines are placed in parallel to the flow rather than perpendicular to the flow .

Generator

We want to use an A.C. generator with 3-Φ windings with increased no. of poles. The poles

will be permanent magnets and the no. of poles will be 8.

This eliminates the need of a gear box in the system.

We shall use a three phase A.C. to D.C. converter to charge the batteries. Cúk converter is

used to give a constant 60V at the output. The current of the converter will vary with the

variation of the speed of the vehicle or the r.p.m of the turbine keeping the terminal voltage

fixed.

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Blades: Most turbines have either two or three blades. Wind blowing over the blades causes

the blades to "lift" and rotate

Generator Usually an off-the-shelf induction generator that AC electricity.

High-speed shaft: Drives the generator.

Rotor:The blades and the hub together are called the rotor.

Fig 9: graph between Power Coefficient (CP) vs Tip Speed Ratio (λ)

Fig source : ars grapik

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Wind turbines typically have two degrees of freedom to optimize power generation.

The ability to change their yaw or compass orientation by turning (using motors) the entire

nacelle unit so the rotor is pointed directly into the wind. This process is controlled by wind

direction information from nearby wind vanes which are located to minimize the effect due to

wake turbulence from the wind turbines.

The pitch of the blades which can be changed to keep a near-constant rotation rate under

varying wind speeds, where the rotation rate is chosen to optimize the power-generation

efficiency of the turbine. Another purpose of both the blade pitch control and yaw

Mechanisms is to act as a brake under extremely strong wind condition.

Cut- in speed: The lowest wind speed at which a wind turbine begins producing usable

power is called cut-in speed. It is about 3m/s.

Cut-out speed: The highest wind speed at which a wind turbine stops producing power is

called cut-out speed. It is about 30m/s.

How do they work?

Wind turbines usually consist of a set of blades attached to a rotor hub, which together form

the rotor; this rotor deflects the airflow, which produces a force on the blades, which in turn

produces a torque on the shaft such that the rotor rotates about a horizontal axis (N.B. this

does not apply to all wind turbines, some rotate about a vertical axis), which is connected to a

gearbox and generator. These are housed in the nacelle (at the top of the tower) with other

electrical components. The generator produces electricity, which is transmitted down the

cables through the tower and out to a transformer, to convert it from the output voltage

(typically around 700V) to the right voltage for either the national grid (33000V) or for

whatever personal use it is being put to (so 240V).

These Horizontal Axis Wind Turbines must always be pointed in the correct direction (into or

away from the wind, depending on the design) if they are to be used efficiently. Those which

face away from the wind – downwind turbines (“downwind” referring to the position of the

turbine relative to the tower) – are blown into the correct orientation. In older and smaller

upwind wind turbines, correct orientation is achieved through use of a simple wind vane;

larger turbines contain a yaw meter and yaw motor. The yaw meter detects the direction of

the wind, and the yaw motor rotates the turbine so that it is always facing into the wind.

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Because it is possible for the turbine to thus yaw in the same direction for many turns,

twisting the cables, turbines have a cable twist counter which causes the system to yaw back

around so that the cables untwist, once they have reached a certain number of turns in one

direction.

Fig 10: Charging and control circuit of the battery. 3Φ windings are used to reduce the ripples. A motor control circuit can be used to control the motor and it will also introduce the provision of Regenerative Braking. Simple Power diodes can be used for designing the converter circuit. The cut-in velocity (minimum wind velocity to generate power) of the turbines is 5m/s.

Fig source: wikipedia

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Calculations ::

Output power from a wind turbine is given by :

PT =( 0.5 CP ρ Q v2 )

Where,

PT = Power output from the turbine in watt.

Cp = Power co-efficient (Assuming, Cp = 0.4 for the design)

ρ = air density; 1.225 kg/m3.

Q = air flow in m3/s.

v = air velocity in m/s.

FOR TURBINE WITH DIA- 40cm

Speed of vehicle 50KMPH (i.e 13.8 m/s)

A = πr2 = 3.1416 × 0.2 =0.12566 m2

Q = Cv A v = 0.25 × 0.8 ×0 .12566 × 13.8 = .3468 m3/s

Here multiplier of Cv is 0.8 as ratio of the inlet and outlet area is 1.38.

Cv is chosen as 0.25 as it is a skewed flow .

So, Power, Pw = .5 ρ Q v2 = .5 × 1.2 × .12566 × 13.8 = 39.6 W

Assuming, Cp = 0.4 Then we have,

PT = 39.6 × 0.4 = 15.85 W ≈ 16 W

So, each turbine will produce a power of 180 W. This much power will be fed back to the battery when it is moving at a constant velocity of 13.8m/s.

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FIG 11: Designs of various radiator grills for different cars

Fig source: Autocad

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FOR DIA =40 cm , Area =0.12566 m2

TABLE NO-1

Power produced at different speeds for automobile

SPEED In KMPH

SPEED IN m/s

Discharge Q

In m3/s

Power PW

In watts

Power PT

(PW×0.4)

In watts

50 13.8 0.3468 39.62 15.85

60 16.6 0.415 6861 27.47

70 19.44 0.4861 110.22 44.08

80 22.22 0.555 164.4 65.76

90 25 0.625 234.37 93.75

100 27.7 0.68 317.6 127

110 30.5 0.7625 425.58 170.23

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FOR DIA =60 cm, Area =0.282744 m2

TABLE NO-2

Comparison of power produced at different speeds

Speed in kmph Speed in m/s Discharge Q

In m3/s

Power PW

In watts

Power PT

(PW×o.4)in

watts

50 13.8 0.78025 89.15 35.66

60 16.6 0.9385 155.5 62.07

70 19.4 1.088 246.7 98.68

80 22.22 1.244 368.5 147.4

90 25 1.4 525 210

100 27.7 1.55 717 286

110 30.5 1.710 957.5 383

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Advantages Of Using Two Turbines

Turbines are placed in such a way that they do not impose or create any additional drag on the vehicle. Symmetrical positioning of the turbine can do the trick as the thrust acting on the turbines will cancel each other.

FIG 12: Resultant thrust generated on wind turbine due to flowing air

Fig source: Wikipedia images

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Conclusion

About 720W energy is required by a automobile ac. From our calculations it is clear that a minimum of 400 W energy can be produced by using a micro wind turbine . Hence the energy can partially automobile ac taken form the engine will be reduced . This will reduce the extra fuel consumption which was used in charging the ac and hence increases mileage . It will furthur reduced the pollution created by the extra fuel consumption .

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1 telosnet.com/wind 

2 Wind turbine Wikkipedia

3 www.journal.elsevier.com

4 www.earth4energy.com

5 Onlinelibrary.wiley.com

6 ZapMeta.co.in(about wind energy)

7 arrow.dit.ie/cgi/viewcontent.cgi?article=1032&context

8 allsmallwindturbines.com 

9 turbomachinery.asmedigitalcollection.asme.org/article

10 www.southampton.ac.uk/.../impact/micro_wind_turbines.page

11 www.ehjournal.net/content/pdf/1476-069X-10-78.pdf

12 www.ehjournal.net/content/pdf/1476-069X-10-78.pdf

13 www.bbc.com/news/uk-scotland-19048787

14 www.gizmodo.com.au/...wind-turbine-to-your-electric-car...

16 gizmodo.com/strap-this-wind-turbine-to-your-electric-car...

17 www.gavinshoebridge.com/electric-car...wind-turbines-on...

18 en.wikipedia.org/wiki/History_of_wind_power  

References

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