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SELF STUDY PROJECT

AUTOMOBILE ENGINEERING 2nd yearSTUDY OF COMPRESSED AIR VEHICHLE

BY:HARMINDER DHILLON: 2K12/AE/037HARSHIT DHAWAN: 2K12/AE/038ISHAN AGGARWAL: 2K12/AE/039ISHANT MEHTA: 2K12/AE/040JALAJ SINGH: 2K12/AE/041Jishnu Mitra: 2K12/AE/045

ABSTRACT

In this modern era we want more comfortable life & to achieve this, there are many inventions and researches are going on in the field of engineering but as each action having there some opposite reaction that may be good or bad. Some achievements may lead to problems in future and one of these achievements is fossil fuel engines which were a good achievement for us before 30-40 years but now they are one of the sources of contributor of global warming and pollution with fossil fuel crises. To cope up with this problem we have to use such engines which emits less or zero COx & NOx particles, for that one of the solutions is hybrid electrical vehicle but again they emit some COx & NOx so this is not a complete solution for this problem. The best feasible solution is Zero Emission Vehicle i.e. Compressed Air Technology (CAT) which does not require any type of fossil fuel. The gasoline-powered engine requires 4 Rs/mile whereas for air powered engines it is 75% less i.e. 1 Rs/mile with no emission COx & NOx pollutants. The cost the hybrid electric vehicle is approximately $50,999 which requires the charging period of 5 to 6 hours whereas the cost of air powered vehicle $14,000 i.e. less than half which requires only 3 to 4 minutes for recharging.

CERTIFICATE

This is to certify that the dissertation entitled STUDY OF COMPRESSED AIR VEHICLE is submitted by combined efforts of following:

1. JALAJ SINGH 2. ISHANT MEHTA3. HARSHIT DHAWAN4. HARMINDER5. ISHAN AGGARWAL6. JISHNU MITRA

For SELF STUDY project. It is also to certify that this project is made for B.Tech in AUTOMOBILE ENGINEERING.

Teacher concerned:

ACKNOWLEDGEMENTS

Every day I remind myself that my inner and outer life depends on the labor of other man- Albert Einstein.Acknowledgment is not a mere obligation but an epitome of humility and indebtness to all those who helped in the compilation of this project and without whom our project would have been anything but presentable.

This is to thank our sincere and respected Professor concerned for inspiring and enthusiastic guidance throughout this project.

Lastly but most important, we would like to pay our utmost regards to our beloved parents and faculty members for their blessing without which success is a mirage.To conclude we would like to quote the following words by Sigmund feud-Dont mix excellence with perfection. Excellence, I can reach for, perfection is gods business

CONTENTS

TopicPage No.

1. Compressed Air Vehicle Basics1.1 Introduction51.2 History61.3 Applications81.4 Advantages91.5 Disadvantages102. Constructional Details112.1 Engine & pneumatic engine and application122.2 Tanks132.3 Compressed air132.4 Emission output143. Working143.1 Process description143.2 Comparison with Electrical Vehicle164. Possible Improvement175. Developers and Manufacturers176. Conclusion197. Bibliography 20

1. 1 Introduction

A Compressed-air engine is a pneumatic actuator that creates useful work by compressed air. A compressed-air vehicle is powered by an air engine, using compressed air, which is stored in a tank. Instead of mixing fuel with air and burning it in the engine to drive pistons with hot expanding gases, compressed air vehicles (CAV) use the expansion of compressed air to drive their pistons.They have existed in many forms over the past two centuries, ranging in size from hand held turbines up to several hundred horsepower. For example, the first mechanically-powered submarine, the 1863 Plongeur, used a compressed air engine.The laws of physics dictate that uncontained gases will fill any given space. The easiest way to see this in action is to inflate a balloon. The elastic skin of the balloon holds the air tightly inside, but the moment you use a pin to create a hole in the balloon's surface, the air expands outward with so much energy that the balloon explodes. Compressing a gas into a small space is a way to store energy. When the gas expands again, that energy is released to do work. That's the basicPrinciple behind what makes an air car go.Some types rely on pistons and cylinders, others use turbines. Many compressed air engines improve their performance by heating the incoming air, or the engine itself. Some took this a stage further and burned fuel in the cylinder or turbine, forming a type of internal combustion engine.One manufacturer claims to have designed an engine that is 90 percent efficient. Compressed air propulsion may also be incorporated in hybrid systems, e.g., battery electric propulsion and fuel tanks to recharge the batteries. This kind of system is called hybrid-pneumatic electric propulsion. Additionally, regenerative braking can also be used in conjunction with this system.

1.2 History

(a) The first compressed-air vehicle was devised by Bompas, a patent for a locomotive being taken out in England in 1828. There were two storage tanks between the frames, with conventional cylinders and cranks. It is not clear if it was actually built. (Knight, 1880)

(b) The first recorded compressed-air vehicle in France was built by the Frenchmen Andraud and Tessie of Motay in 1838. A car ran on a test track at Chaillot on the 9th July 1840, and worked well, but the idea was not pursued further.

Fig: 1.1

(c) In 1848 Barin von Rathlen constructed a vehicle which was reported to have been driven from Putney to Wandsworth (London) at an average speed of 10 to 12 mph.

(d) At the end of 1855, a constructor called Julienne ran some sort of vehicle at Saint-Denis in France, driven by air at 25 atmospheres (350 psi), for it to be used in coal mines.

(e) Compressed air locomotives were use for haulage in 1874 while the Simplon tunnel was being dug. An advantage was that the cold exhaust air aided the ventilation of the tunnel.

(f) Louis Mkarski built a standard gauge self-contained tramcar which was tested in February 1876 on the Courbevoie-Etoile Line of the Paris Tramways Nord (TN), where it much impressed the current president and minister of transport Marchal de MacMahon. The tramcar was also shown at the exhibition of 1878 as it seemed to be an ideal transport method, quiet, smooth, without smoke, fire or the possibility of boiler explosion.

(g) The compressed-air locos were soon withdrawn due to a number of accidents, possibly caused by icing in the pipes of the brakes, which were also worked by compressed air.

(h) In Louis Mkarski built a standard gauge self-contained tramcar which was tested in February 1876 on the Courbevoie-Etoile Line of the Paris Tramways Nord (TN), where it much impressed the current president and minister of transport Marchal de MacMahon. The tramcar was also shown at the exhibition of 1878 as it seemed to be an ideal transport method, quiet, smooth, without smoke, fire or the possibility of boiler explosion.

Fig 1.2 TheVictor Tatinairplane of 1879 used a compressed-air engine for propulsion

1.3 Applications

The compressed air engine can be used in many vehicles. Some of its applications to be used as engine for vehicles are:

(a) MopedsJem Stansfield, an English inventor has been able to convert a regular scooter to a compressed air moped. This has been done by equipping the scooter with a compressed air engine and air tank.

(b) BusesMDI makes MultiCATs vehicle that can be used as buses or trucks. RATP has also already expressed an interest in the compressed-air pollution-free bus.

(c) LocomotivesCompressed air locomotives have been historically used as mining locomotives and in various areas.

(d) TramsVarious compressed-air-powered trams were trialed, starting in 1876 and has been successfully implemented in some cases.

(e) Watercraft and aircraftCurrently, no water or air vehicles exist that make use of the air engine. Historically compressed air engines propelled certain torpedoes.

1.4 Advantages

The advantages are well publicized since the developers need to make their machines attractive to investors. Compressed-air vehicles are comparable in many ways to electric vehicles, but use compressed air to store the energy instead of batteries. Their potential advantages over other vehicles include:(a) Much like electrical vehicles, air powered vehicles would ultimately be powered through the electrical grid, which makes it easier to focus on reducing pollution from one source, as opposed to the millions of vehicles on the road.

(b) Transportation of the fuel would not be required due to drawing power off the electrical grid. This presents significant cost benefits. Pollution created during fuel transportation would be eliminated.

(c) Compressed air technology reduces the cost of vehicle production by about 20%, because there is no need to build a cooling system, fuel tank, Ignition Systems or silencers.(d) Air, on its own, is non-flammable.

(e) High torque for minimum volume.

(f) The mechanical design of the engine is simple and robust.

(g) Low manufacture and maintenance costs as well as easy maintenance.

(h) Compressed-air tanks can be disposed of or recycled with less pollution than batteries.

(i) Compressed-air vehicles are unconstrained by the degradation problems associated with current battery systems.

(j) The tank may be able to be refilled more often and in less time than batteries can be recharged, with re-fuelling rates comparable to liquid fuels.

(k) Lighter vehicles would mean less abuse on roads. Resulting in longer lasting roads.

(l) The price of fuelling air-powered vehicles will be significantly cheaper than current fuels.

1.5 Disadvantages

Like the modern car and most household appliances, the principal disadvantage is the indirect use of energy. Energy is used to compress air, which - in turn - provides the energy to run the motor. Any conversion of energy between forms results in loss. For conventional combustion motor cars, the energy is lost when oil is converted to usable fuel - including drilling, refinement, labour, storage, eventually transportation to the end-user. For compressed-air cars, energy is lost when electrical energy is converted to compressed air.

(a) When air expands, as it would in the engine, it cools dramatically (Charles law) and must be heated to ambient temperature using a heat exchanger similar to the Intercooler used for internal combustion engines. The heating is necessary in order to obtain a significant fraction of the theoretical energy output. The heat exchanger can be problematic. While it performs a similar task to the Intercooler, the temperature difference between the incoming air and the working gas is smaller. In heating the stored air, the device gets very cold and may ice up in cool, moist climates.

(b) Refueling the compressed air container using a home or low-end conventional air compressor may take as long as 4 hours though the specialized equipment at service stations may fill the tanks in only 3 minutes.

(c) Tanks get very hot when filled rapidly. SCUBA tanks are sometimes immersed in water to cool them down when they are being filled. That would not be possible with tanks in a car and thus it would either take a long time to fill the tanks, or they would have to take less than a full charge, since heat drives up the pressure.

(d) Early tests have demonstrated the limited storage capacity of the tanks; the only published test of a vehicle running on compressed air alone was limited to a range of 7.22 km.

(e) A 2005 study demonstrated that cars running on lithium-ion batteries outperform both compressed air and fuel cell vehicles more than three-fold at same speeds. MDI has recently claimed that an air car will be able to travel 140km in urban driving, and have a range of 80 km with a top speed of 110km/h on highways, when operating on compressed air alone.

2. CONSTRUCTIONAL DETAILS

Fig.2.1:- Chassis of air powered carIn practical terms compressed air at 300 bars is stored in the carbon fibre tanks A. The air is released through the main line firstly to an alternator B where the first stage of decompression takes place. The now cold air passes through a heat exchanger C which adds thermal energy to the air and provides a convenient opportunity for air conditioning D. The warmed compressed air now passes to the motor E. where a two more stages of decompression and re-heating take place. The motor drives the rear axle G through the transmission F. Control of engine speed is through a conventional accelerator pedal H controlling a valve within the motor.An energy recycler J is under test which uses engine braking K to recompress air during braking into a secondary storage facility, providing additional energy for re-start and acceleration. Conventional hydraulic braking L is supplied. The vehicle can be refilled by using the onboard compressor M or by refilling the tank at an air station at N. Ultimately the engine generates 37 Kilowatts, notwithstanding the small size of this unit. The "exhaust" leaves the engine at about zero degrees Celsius, a result of the expansion and cooling action. The exhaust is totally pure and fit to breathe. A compressed air driven engine offers enormous benefits to the car designer. Because of its small size and weight, and the removal of a host of devices and parts not required, the designer has free rein to maximize his materials and space to provide a simple, economic platform for the vehicle.2.1 Engine & pneumatic engine and application

Fig.2.2 Pneumatic hybridization of Diesel EngineApneumatic motororcompressed air engineis a type ofmotorwhich doesmechanical workby expandingcompressed air. Pneumatic motors generally convert the compressed air energy to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor.Pneumatic motors have existed in many forms over the past two centuries, ranging in size from hand-held turbines to engines of up to several hundred horsepower. Some types rely on pistons and cylinders; others use turbines. Many compressed air engines improve their performance by heating the incoming air or the engine itself. 2.2 Tanks

The storage vessel is often an underground cavern created bysolution mining(salt is dissolved in water for extraction)or by utilizing an abandonedmine; use of porous rock formations such as those in which reservoirs of natural gas are found has also been studied.Plants operate on a daily cycle, charging at night and discharging during the day. Heating of the compressed air using natural gas or geothermal heat to increase the amount of energy being extracted has been studied by thePacific Northwest National Laboratory

Fig. 2.3 Compressed Air CylinderCompressed air energy storage can also be employed on a smaller scale such as exploited byair carsand air-drivenlocomotives, and also by the use of high-strengthcarbon-fiberair storage tanks. However, when compressed air is stored atroom temperaturethis stored air, in general, contains the same amount of energy per pound as uncompressed room temperature air. The considerable amount of energy used to compress this airis not stored thereif the air is allowed to reduce to room temperature. Therefore, to obtain substantial energy from the expansion of this stored room temperature compressed air a heat reservoir must be provided to supply the needed energy. This can be challenging in mobile applications.

2.3 Compressed AirCompressed airhas a lowenergy density. In 300 bar containers, about 0.1 MJ/L and 0.1 MJ/kg is achievable, comparable to the values of electrochemical lead-acid batteries. While batteries can somewhat maintain their voltage throughout their discharge and chemical fuel tanks provide the same power densities from the first to the last litre, the pressure of compressed air tanks falls as air is drawn off. A consumer-automobile of conventional size and shape typically consumes 0.30.5 kWh (1.11.8 MJ) at the drive shaft per mile of use, though unconventional sizes may perform with significantly less.

2.4 Emission outputLike other non-combustion energy storage technologies, an air vehicle displaces the emission source from the vehicle's tail pipe to the central electrical generating plant. Where low emissions sources are available, net production of pollutants can be reduced. Emission control measures at a central generating plant may be more effective and less costly than treating the emissions of widely dispersed vehicles.Since the compressed air is filtered to protect the compressor machinery, the air discharged has less suspended dust in it, though there may be carry-over of lubricants used in the engine.3. Working

In principle the technology is very similar to the internal combustion system in that compressed air is used to drive a piston in a barrel. The secret of the engine lies in the way it efficiently converts the energy stored in the tanks of compressed air.By way of explanation, it has long been known that to compress air to high pressures a staged process should be used, compressing air to first 50 bars, then to 150 bars then three hundred and so on. This technique, commonly employed by the air and gas liquefaction industries, uses a fraction of the energy used to compress the gas in one operation. The secret of the compressed air motor is simply to reverse the process - decompress the air in stages and in so doing efficiently release energy at each point in the chain. 3.1 PROCESS DESCRIPTION1. The first piston takes in ambient air compressed it to approximately 300psi and 200F in the compression chamber during the first cycle of engine

Fig.3.1 working of air operated engine2. When the piston pauses, a small amount of compressed air from the tanks is released into the expansion chamber to create a low pressured, low temperature volume of about 140 psi.3. Shortly before the valve to the expansion cylinder is opened a high-speed shutter connects the compression and expansion chambers this sudden pressure and temperature difference between the two chambers creates pressure waves in the expansion chamber, thereby producing work in the expansion cylinder that drives the piston to power the engine The air tanks for storing the compressed are located underneath the vehicle they are constructed of reinforced carbon fiber with a thermoplastic liner each tank can held 3180 ft3 of air at a pressure of up to 4,300 psi when connected to a special compressor station the tanks can be recharged within 3-4 mints they can also be recharged using the on-board compressor within 3-4 hours after connection to standard power outlet.To Fig.3.2 flow of air tank to exhaustCompensate for the cooling effect that takes place, a thermal exchanger heats the compressed air using the warmth of external air. This process is repeated as many times as possible to extract the maximum energy efficiency from the compressed air. For the somewhat technically minded, the following drawing illustrates the theoretical explanation for this process.3.2 COMPARISON WITH ELECTRICAL VEHICLES

Fig 3.3 Comparison between air car and electric vehicleCompressed-air vehicles are comparable in many ways toelectric vehicles, but use compressed air to store the energy instead of batteries. Their potential advantages over other vehicles include: Much like electrical vehicles, air powered vehicles would ultimately be powered through the electrical grid. Which makes it easier to focus on reducing pollution from one source, as opposed to the millions of vehicles on the road Transportation of the fuel would not be required due to drawing power off the electrical grid. This presents significant cost benefits. Pollution created during fuel transportation would be eliminated. Compressed-air technology reduces the cost of vehicle production by about 20%, because there is no need to build acoolingsystem, fuel tank, Ignition Systems orsilencers. The engine can be massively reduced in size The engine runs on cold or warm air, so can be made of lower strength light weight material such asaluminium, plastic, low frictionteflonor a combination.

Low manufacture and maintenance costs as well as easy maintenance. Compressed-air tanks can be disposed of or recycled with less pollution than batteries. Compressed-air vehicles are unconstrained by the degradation problems associated with current battery systems. The air tank may be refilled more often and in less time than batteries can be recharged, with re-filling rates comparable to liquid fuels. Lighter vehicles cause less damage to roads, resulting in lower maintenance cost. The price of filling air powered vehicles is significantly cheaper than petrol, diesel or biofuel. If electricity is cheap, then compressing air will also be relatively cheap.

4. Possible Improvements

Compressed-air vehicles operate to athermodynamic processas air cools down when expanding and heats up when being compressed. As it is not possible in practice to use a theoretically ideal process, losses occur and improvements may involve reducing these, e.g., by using large heat exchangers in order to use heat from the ambient air and at the same time provide air cooling in the passenger compartment. At the other end, the heat produced during compression can be stored in water systems, physical or chemical systems and reused later. It may be possible to store compressed air at lower pressure using an absorption material within the tank. Absorption materials such asActivated carbon,or ametal organic frameworkis used to storecompressed natural gasat 500 psi instead of 4500 psi, which amounts to a large energy saving

5. Developers and Manufacturers

Various companies are investing in theresearch, development and deploymentofCompressed air cars. Overoptimistic reports of impending production date back to at least May 1999. For instance, the MDI Air Car made its public debut inSouth Africain 2002,and was predicted to be in production "within six months" in January 2004.As of January 2009, the air car never went into production in South Africa. Most of the cars under development also rely on using similar technology toLow-energy vehiclesin order to increase the range and performance of their cars.APUQAPUQ (Association de Promotion des Usages de la Quasiturbine) has made the APUQ Air Car, a car powered by a Quasiturbine.MDIMDIhas proposed a range of vehicles made up of AirPod, OneFlowAir, CityFlowAir, MiniFlowAir and MultiFlowAir.One of the main innovations of this company is its implementation of its "active chamber", which is a compartment which heats the air (through the use of a fuel) in order to double the energy output.This 'innovation' was first used intorpedoesin 1904.TATA MotorsAs of January 2009Tata MotorsofIndiahad planned to launch a car with an MDI compressed air engine in 2011.In December 2009 Tata's vice president of engineering systems confirmed that the limited range and low engine temperatures were causing problems.Tata Motors announced in May 2012that they have assessed the design passing phase 1, the "proof of the technical concept" towards full production for the Indian market. Tata has moved onto phase 2, "completing detailed development of the compressed air engine into specific vehicle and stationary applications".Air Car Factories SAAir Car Factories SA is proposing to develop and build a compressed air engine.This Spanish based company was founded by Miguel Celades. Currently there is a bitter dispute betweenMotor Development International, another firm called Luis which developed compressed-air vehicles, and Mr. Celades, who was once associated with that firm. EnergineTheEnergine Corporationwas a South Korean company that claimed to deliver fully assembled cars running on a hybrid compressed air and electric engine. These cars are more precisely named pneumatic-hybrid electric vehicles.Engineers from this company made, starting from a Daewoo Matiz, a prototype of a hybrid electric/compressed-air engine (Pne-PHEV,pneumaticvehicle the compressed-air engine is used to activate an alternator, which extends the autonomous operating capacity of the car.A similar concept using a pneumatic accumulator in a largely hydraulic system has been developed by U.S. government research laboratories and industry. It uses compressed air only for recovery of braking energy, and in 2007 was introduced for certain heavy vehicle applications such as refuse trucks.Honda

Fig.4.1 PSA Peugeot Citron Hybrid Air concept exhibited at the 2013Geneva Motor Show.

In 2010, Honda presented theHonda Airconcept car at the LA Auto Show.KernelysThe "K'Airmobiles" project of Kernelysaimed to produce commercial vehicles in France. The project was started in 2006-2007 by a small group of researchers. They said to be working on 2 types of vehicles; namely "VPA" (Vehicles with Pneumatic Assistance) and "VPP" (Vehicles with Pneumatic Propulsion) vehicles.However, the project has in the end not been able to gather the necessary funds to go commercial.People should note that, meantime, the team has recognized the physical impossibility to use on-board stored compressed air due to its poor energy capacity and the thermal losses resulting from the expansion of the gas.These days, using the patent pending 'K'Air Fluid Generator', converted to work as a compressed-gas motor, the company has reworked its project in 2010 together with a North American group of investors, now intended for the purpose of developing a green energy power system.EngineairEngineair is an Australian company which manufactures small industrial vehicles using an air engine of its own design.Peugeot/CitronPeugeot and Citron have announced that they too are building a car that uses compressed air as an energy source. However, the car they are designing uses a hybrid system which also uses a gasoline engine (which is used for propelling the car over 70km/h, or when the compressed air tank has been depleted.

6. CONCLUSION

Nowadays the earth is facing the biggest problem of global warming. The major cause for this is the environmental pollution. Fossil fuel vehicles are the major contributors to this pollution. In order to irradiate this problem the solution is hybrid electrical vehicles but again they emit some pollutants, hence it is not a complete solution. The compressed air technology i.e. zero emission vehicles is the best feasible alternative and hence the complete solution of this problem.

7. Bibliography

http://www.theaircar.com/ http://auto.howstuffworks.com/air-car.htm http://www.planetsave.com/ViewStory.asp?ID=24 http://www.evworld.com/databases/shownews.cfm?pageid=news040303-06 http://news.bbc.co.uk/1/hi/world/europe/2281011.stm htto://zevcat.com/

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