ABSTRACT The Air Driven Engine is an eco-friendly engine which operates with compressed air. An Air Driven Engine uses the expansion of compressed air to drive the pistons of an engine An Air
Driven
Engine is
a pneumatic
actuator that
creates
useful
work
by
expanding compressed air. There is no mixing of fuel with air as there is no combustion. co mbustion.
An Air Driven Engine makes use of Compressed Air Technology for its operation The Compressed Air Technology is uite simple. !f we compress normal air into a cylinder the air would hold some energy within it. This energy can be utili"ed for useful purposes. #hen this compressed air expands$ the energy is released to do work. %o this energy in compressed air can also be utili"ed to displace a piston
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CHAPTER 1
INTRODUCTION At first glance the idea of running an engine on air seems to be too good to be true. Actually$ if we can make use of air as an aid for running an engine it is a fantastic idea. As we all know$ air is all around us$ it never runs out$ it is non-polluting and it is free.
An Air Air Driv Driven en Engi Engine ne makes makes use use of Comp Compre ress ssed ed Air Air Techn Technol ology ogy for for its its oper operat atio ion. n. Compressed Air Technology is now widely preferred for research by different industries for developing different drives for different purposes. The Compressed Air Technology is uite simple. !f we compress normal air into a cylinder the air would hold some energy within it. This energy can be utili"ed for useful purposes. #hen this compressed air expands$ the energy is released to do work.
%o this energy in compressed air can also be utili"ed to displace a piston. This is the basic working principle of the Air Driven Engine. !t uses the expansion of compressed air to drive the pistons of the engine. %o an Air Driven Engine is basically a pneumatic actuator that creates creates useful work by expanding expanding compressed air. This work provided by the air is utili"ed to supply power to the crankshaft of the engine.
!n the case of an Air Driven Engine$ there is no combustion taking place within the engine. %o it is non-polluting and less dangerous. !t reuires lighter metal only since it does not have to withstand elevated temperatures.
As there is no combustion taking place$ there is no need for mixing fuel and air. (ere compressed air is the fuel and it is directly fed into the piston cylinder arrangement. !t simply expands inside the cylinder and does useful work on the piston. This work done on the piston provides sufficient power to the crankshaft.
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CHAPTER 2
LITERATURE REVIEW 2.1. COMPRESSED AIR TECHNOLOGY Air can be compressed into small volumes and can be stored in suitable containers at high pressures. %uch air compressed into containers is associated associated with an amount of energy. #hen the stored compressed air is released freely it expands thereby releasing the energy associated with it. This energy released can be utili"ed to provide useful work.
The compression$ storage and release of the air together are termed as the Compressed Air Technol Technology. ogy. This This techno technolog logy y has been been utili" utili"ed ed in differ different ent pneuma pneumatic tic system systems. s. This This technology has been undergoing several years of research to improve its applications.
Compressed air is regarded as the fourth utility$ after electricity$ natural gas$ and water. Compressed air can be used in or for*
'neumatics$ the use of pressuri"ed gases to do work.
vehicular transportation using a compressed air vehicle
scuba diving
To inflate buoyancy devices.
Cooling using a vortex tube.
+as dusters for cleaning electronic components that canno t be cleaned with water.
air brake ,rail systems
air brake ,road vehicle systems
starting of diesel engines ,an alternative to electric starting
compressed air breathers ,such as %uisse Air
pneumatic air guns
pneumatic screwdrivers
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2.2. TWO STROKE ENGINE A two-stroke engine is an internal combustion engine that completes the thermodynamic in two movements of the piston piston compared compared to twice that number for a four-stroke four-stroke engine. This increased increased efficiency efficiency is accomplishe accomplished d by using the beginning of the compression compression stroke and the the end end of the the comb combus usti tion on stro stroke ke to perf perfor orm m simu simult ltan aneou eousl sly y the the inta intake ke and exha exhaus ustt ,or ,or scave scaveng ngin ing g func functi tion ons. s. !n this this way way twotwo-st stro roke ke engi engine ness ofte often n prov provid idee stri striki king ngly ly high specific power. +asoline ,spark ignition versions are particularly useful in lightweight ,portable applications such as chainsaws and the concept is also used in diesel compression igni igniti tion on engin engines es in larg largee and nonnon-we weig ight ht sens sensit itiv ivee appl applic icat atio ions ns such such as ship shipss and and locomotives.
All functions are controlled solely by the piston covering and uncovering the ports as it moves up and down in the cylinder. A fundamental difference from typical four-stroke engines is that the crankcase is sealed and forms part of the induction process in gasoline and hot bulb bulb engine engines. s. Diesel Diesel engine enginess have have mostl mostly y a roots roots blower blower or piston piston pump pump for scavenging.
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0ig. ).& working of two stroke engine en gine There are no traditional valves in a two-stroke engine. !n a two-stroke the engines fires once every revolution. This makes the engine highly efficient and lightweight compared to fourstroke stroke systems. systems. 1ather than entering entering through valves$ valves$ the fuel2air mixture mixture enters enters through through an intake port and exhaust exits out of an exhaust port. !n place of traditional valves the twostroke engine uses the piston3s position to force out exhaust or suck in fuel mixture. 1eeds are vital to a two-stroke system. The reeds are placed between the intake manifold and the carburetor$ open and close to allow the fuel 2 air mixture to enter the case of the engine and trap it$ and ensure the proper exchange of gasses in the engine. This procedure might sound complex$ but it is$ in fact$ extremely effective and easy to understand. The whole cycle can be explained as follows* & As the piston moves from bottom dead center to top dead center it creates a vaccum to draw the fuel 2 air mixture through the carburetor and past the reed valve assembly. a ssembly.
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) The piston moves down from top dead center to bottom dead center. The reed closes$ causing the pressure to build in the cylinder. The movement of the piston uncovers the intake port and pressuri"ed the fuel 2 air mixture. The piston now moves up from bottom dead center to top dead center$ effectively ending a cycle and starting another. The spark plug ignites the compressed mixture$ sending piston back down. / At this point the piston uncovers the exhaust port$ allowing the spent gasses to escape. As it continues to bottom dead center$ it uncovers the intake port and allows the fuel 2 air mixture through the carburetor and past the reed valve assembly.
2.3. SOLENOID VALVE
A soleno solenoid id valve valve is an electr electrome omecha chanica nicall valve valve for use with with liuid liuid or gas. gas. The valve valve is controlled by an electric current through a solenoid coil. %olenoid valves may have two or more ports* in the case of a two-port valve the flow is switched on or off5 in the case of a three-port valve$ the outflow is switched between the two outlet ports. 6ultiple solenoid valves can be placed together on a manifold. %olenoid valves are the most freuently used control elements in fluidics. Their tasks are to shut off$ release$ dose$ distribute or mix fluids. They are found in many application areas. %olenoids offer fast and safe switching$ high reliability$ long service life$ good medium compatibility of the materials used$ low control power and compact design. A solenoid valve has two main parts* the solenoid and the valve. The solenoid converts elec electr tric ical al ener energy gy into into mech mechani anica call ener energy gy which which$$ in turn turn$$ open openss or clos closes es the the valve valve mechanically. A direct acting valve has only a small flow circuit$ shown within section E of this diagram. This diaphragm piloted valve multiplies this small flow by using it to control the flow through a much larger orifice.
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%olenoid valves may use metal seals or rubber seals$ and may also have electrical interfaces to allow for easy control. A spring may be used to hold the valve opened or closed while the valve is not activated.
fig. ).) working of solenoid valve A- Input side B- Diaphragm C- Pressure chamber D- Pressure relief conduit E- Solenoid F- Output side
The diagram above shows the design of a basic valve. At the top figure is the valve in its closed state. The water under pressure enters at A. B is an elastic diaphragm and above it is a weak spring pushing it down. The function of this spring is irrelevant for now as the valve would stay closed even without it. The diaphragm has a pinhole through its center which allows a very small amount of water to flow through it. This water fills the cavity Con the other side of the diaphragm so that pressure is eual on both sides of the diaphragm. #hile the pressure is the same on both sides of the diaphragm$ the force is greater on the upper side 8 | ' a g e
which forces the valve shut against the incoming pressure. !n the figure$ the surface being acted upon is greater on the upper side which results results in greater greater force. 9n the upper side the pressure is acting on the entire surface of the diaphragm while on the lower side it is only acting on the incoming pipe. This result in the valve being securely shut to any flow and$ the greater the input pressure$ the greater the shutting force will be. !n the previo previous us config configura uratio tion n the small small condui conduitt D was blocked by a pin which is the armatu armature re of the soleno solenoid id E and which is pushed down by a spring. !f the solenoid is activated by drawing the pin upwards via magnetic force from the solenoid current$ the water in chamber C will flow through this conduit D to the output side of the valve. The pressure in chamber C will drop and the incoming pressure will lift the diaphragm thus opening the main valve. #ater now flows directly from A to F. #hen the solenoid is again deactivated and the conduit D is closed again$ the spring needs very little force to push the diaphragm down again and the main valve closes. !n practice there is often no separate spring$ the elastomer diaphragm is moulded so that it functions as its own spring$ preferring to be in the closed shape. 0rom this explanation it can be seen that this type of valve relies on a differential of pressure between input and output as the pressure at the input must always be greater than the pressure at the output for it to work. !f the pressure at the output$ for any reason$ rise above that of the input then the valve would open regardless of the state of the solenoid and pilot valve. !n some solenoid valves the solenoid acts directly on the main valve. 9thers use a small$ complete solenoid valve$ known as a pilot$ to actuate a larger valve. #hile the second type is actually a solenoid valve combined with a pneumatically actuated valve$ they are sold and packaged as a single unit referred to as a solenoid valve. 'iloted valves reuire much less power to control$ but they are noticeably slower. 'iloted solenoids usually need full power at all times to open and stay open$ where a direct acting solenoid may only need full power for a short period of time to open it$ and only low power to hold ho ld it. %olenoi %olenoid d valves valves are used used in fluid fluid power power pneumat pneumatic ic and hydrau hydraulic lic system systems$ s$ to control control cyli cylind nder ers$ s$
flui fluid d
powe powerr
moto motors rs
or
larg larger er
indu indust stri rial al
valv valves es..
Auto Automa mati ticc irri irriga gati tion on
sprinkler systems also use solenoid valves with an automatic controller. Domestic washing : | ' a g e
machines and dishwashers use solenoid valves to control water entry to the machine. !n the paintball industry$ solenoid valves are usually referred to simply as ;solenoids.; They are commonly used to control a larger valve used to control the propellant ,usually compressed air
or
C9).
!n
the
industry$
;solenoid;
may
also
refer
to
an
electromechanical solenoid commonly used to actuate a sear.
2.4. AIR COMPRESSOR An air compressor is a device that converts electrical power or gas into kinetic energy by pressuri"ing and compressing air$ which is then released in uick bursts. There are numerous methods methods of air compre compressi ssion$ on$ divide divided d into into either either positi positive-d ve-dis ispla placem cement ent or non-po non-posi sitiv tivee displacement types. 'ositive-displacement air compressors work by forcing air into a chamber whose volume is reduced to effect the compression. 'iston-type air compressors use this principle by pu mping air air into into an air air chamb chamber er thro throug ugh h the the use use of the the cons consta tant nt moti motion on of pist piston ons. s. They They use use unidirectional valves to guide air into a chamber$ where the air is compressed. 1otary screw compressors also use positive-displacement compression by matching two helical screws that$ when turned$ guide air into a chamber$ the volume of which is reduced as the screws turn. =ane compressors use a slotted rotor with varied blade placement to guide air into a chamber and compress the volume. >on-positive-displacement air compressors include centrifugal compressors. These devices use centrifugal force generated by a spinning impeller to accelerate and then decelerate captured air$ which pressuri"es it. The air compressors seen by the public are used in 4 main applications*
To supply a high-pressure clean air to fill gas cylinders
To supply supply a modera moderatete-pre press ssure ure clean clean air to supply supply air to a submer submerged ged surfac surfacee supplied diver
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To supply a large amount of moderate-pressure air to power pneumatic tools
0or filling tires
To produce produce large large volume volumess of modera moderatete-pre pressu ssure re air for macros macroscop copic ic indust industri rial al processes ,such as oxidation for petroleum coking or cement plant bag house purge systems.
6ost air compressors are either reciprocating piston type or rotary vane or rotary screw. Centrifugal compressors are common in very large applications. There are two main types of air compress compressor@ or@ss pumps* pumps* 9il lubed and oiless oiless.. The oiless oiless system system has more more techni technical cal development$ but they are more expensive$ louder and last less than the oiled lube pumps.
2.5. INFRARED PAIR The infrared pair mainly consists of an infrared emitter and an infrared sensor. The infrared emitter emits the infrared rays to the infrared sensor. The sensor senses the infrared rays which are emitted emitted by the emitter. emitter.
0ig. ). !1 pair
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CHAPTER 3
THE COMPONENTS The maor components of our Air Driven Engine consist of*
&. T(E E> E>+!>E ). T(E T(E %9E %9E>9 >9!D !D =A =A=E =E . T(E T(E =A= =A=E E ACT ACTAT AT!9 !9> > %%T %%TE6 E6 /. T(E T(E '! '!'E %%T %%TE6 E6 4. T(E T(E '1E% '1E%% %1E 1E +A +A+E +E %% %%TE TE6 6
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CHAPTER 4
THE ENGINE The basic engine that we have h ave used in the proect is a normal two stroke petrol engine. The details of the engine are as follows* 6ake*
o. of cylinders* &
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0ig. /.& The Engine
#e only needed a simple piston-cylinder arrangement with an outlet and an exhaust.
Closing the transfer port
•
Closing the inlet port
•
1emoving the spark plug from the cylinder head
•
'roviding an inlet at the place of the spark plug
•
'roviding a suitable connector at the cylinder head
The transfer port was to be sealed to provide maximum sealing of the piston-cylinder arrangement so that the chances of escape of air from the cylinder can be avoided. #e made use of m-seal and araldite to seal off the transfer port. 0irst a fine uantity of m-seal was & | ' a g e
filled in the transfer port fully except for a small clearance to apply araldite. Then the m-seal was allowed to solidify. After that araldite was applied in another layer and was allowed to solidify. Thus the transfer port was closed with the help of the adhesives.
0ig. /.) Cylinder
There is no combustion combustion taking place in an Air Driven Engine. %o naturally naturally there is no need for the spark plug. %o the spark plug is removed from its respective position that is on the top of cylinder head. !t would be great if we provide the inlet for compressed air at the position of the spark plug as it is better to let the air enter from the top of the piston. %o the connector which is used to connect the pipe from the compressed air tank has to be fixed at the position of the spark plug. The connector contains an 1&2) thread of <%'T standard. %o
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we tapped the same thread on the cylinder head at the position of the spark plug. Then the suitable connector was fixed on the cylinder head.
0ig /. Cylinder (ead
CHAPTER 5
THE SOLENOID VALVE A soleno solenoid id valve valve is an electr electrome omecha chanica nicall valve valve for use with with liuid liuid or gas. gas. The valve valve is contro controlle lled d by an electr electric ic curren currentt through through a soleno solenoid id coil. coil. %oleno %olenoid id valves valves are the most most
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freue freuentl ntly y used used contro controll element elementss in fluid fluidics ics.. Their Their tasks tasks are to shut shut off$ off$ releas release$ e$ dose$ dose$ distribute or mix fluids. They are found in many application areas.
0or controlling the air flow in and out of the engine we use a 2) pilot operated normally closed valve. The symbol of the 2) valve is as shown*
0ig 4.& =alve %ymbol The specifications of the valve are the following*
•
9rifice* &)mm.
•
9perating pressure range* )-&Bbar
•
0low rate* BBBitres2minute
•
Coil width* )mm.
•
=oltage* )/= DC
•
Duty cycle* Continuous
The 2) solenoid valve utili"ed in our proect is shown in the following picture*
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0ig. 4.) The %olenoid =alve
The construction and the working of the 2) solenoid valve can be explained with the help of the following diagram*
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0ig 4. Construction and #orking
The figure shows the operation of a pilot operated 2) pneumatic valve. The solenoid operates the small pilot valve directly.
#hen the solenoid de-energi"es$ the space above the control valve is vented. ine and spring pressure on the main valve causes the valve stem to rise again.
CHAPTER 6
VALVE ACTUATION SYSTEM
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The valve actuation system is the system used to actuate the valve mechanism. The valve here used is a 2) solenoid valve. This valve we used here is an always closed valve. This valve works only when a high voltage is applied to it. >ormally this high voltage is 4v. The supply voltage of this valve is )/v. The high voltage for the opening of the valve is provided by the circuit. #hen a high voltage is applied to the valve it gets open. The main components of the valve actuation system are the following &. !nfr nfrared ared pai pair •
!nfrared emitter
•
!nfrared sensor
). Elec Electr tron onic ic circ circui uitt .
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6.1. INFRARED PAIR The infrared pair mainly consists of an infrared emitter and an infrared sensor. The infrared emitter emits the infrared rays to the infrared sensor. The sensor senses the infrared rays which are emitted by the emitter.
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0ig. 7.) !1 'air position
The figure shows the arrangements of the infrared sensors placed at face to face. They are arranged on a flexible aluminum sheet so that they can be adusted as reuired. They need to be at sufficient distance apart to avoid collision with the the disc.
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6.2. THE ELECTRONIC CIRCUIT The electronic circuit mainly consists of the following components namely &. 'ower su supply ). 'owe 'owerr supp supply ly conne connect ctor or . =olt =oltag agee regu regula lato tor r /. 1esistors 4. =olt =oltag agee divi divide der r 7. !nfr !nfrar ared ed emit emitte terr connec connecto tor r 8. !nfr !nfrar ared ed sens sensor or conn connec ecto tor r :. Transistor ?. =alv =alvee conn connec ecto tor r &B. Compar Comparato ator r
0ig. 7. The circuit
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7.).&. '9#E1 %'' The power supply used here is a )/v supply. This voltage is provided by two batteries each of )/v and ).4A rating. These batteries are connected in series.
7.).). '9#E1 %'' C9>>ECT91% The The circ circui uitt is prov provid ided ed with with a conne connect ctor or whic which h is a two two sock socket et conn connec ecto tor. r. The The male male connector is placed in the electronic circuit and the female connector is provided at the other end. The power supply connectors conn ectors are soldered to the circuit.
7.).. =9TA+E 1E+AT91 The voltage regulator used here is 1+ 8:B4. This voltage regulator has three terminals namely •
1eference
•
!nput
•
9utput
The reference terminal is grounded and the input terminal is provided with the supply. This circuit converts the )/v dc into 4v dc. All the components in this circuit only work on 4v. Thus the )/v need to be stepped down to 4v in order to avoid burning of the circuit components. This 4v is taken out through the output terminal.
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0ig.7./ =oltage 1egulator
7.)./. 1E%!%T91% The resistors are used to step down the current from the main supply. The main resistors used are the following.
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•
&BBG
•
/8B
•
&BG
•
&G
•
&4BH)
0ig. 7.4 1esistors The figure figure shows shows the &BBG &BBG resist resistor. or. This This compone component nt is connec connected ted before before the voltage voltage regulator to step down the high current of )/ v supply.
7.).4. =9TA+E D!=!DE1% The voltage dividers are used to divide the voltage according to the purpose. An eual amount of resistors can be used to divide the circuit. (ere two &4BG resistors are used to divide the 4v to ).4v dc to be supplied to the comparator.
0ig 7.7 =oltage Divider
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7.).7. T1A>%!%T91% The transistor here used is B4. This component is used as a switching device to switch the 4v to the solenoid valve. !t consists of three terminals. The emitter is grounded. The base is connected to the output terminal ,& of the comparator and the collector terminal of the transistor is connected to the solenoid valve.
0ig 7.8 Transistor
7.).8. C96'A1AT91 The comparator here used is lm 4):. !t mainly consists of : terminals out of which 4 terminals are in use. The negative terminal is connected to the voltage divider and the positive terminal is connected to the sensor. The output is taken from the output terminal to the transistor which acts as a switching device. The fourth terminal is grounded and the eighth terminal is given the 4v supply.
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0ig 7.: The 4 terminals used are the following •
>egative terminal,)
•
'ositive terminal,
•
9utput terminal,&
•
+round terminal,/
•
%upply terminal,:
0ig 7.? Comparator
6.3. BATTERIES
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The batteries used here have a rating of &)v$ ).4A. The solenoid valve works only on )/v. (ence the batteries need to be connected in series to obtain )/v.
0ig 7.&B
6.4. WIRING SYSTEM The wiring system mainly consists of wires that are used to connect the components in the actuation system
6.5. VALVE TIMING DISC The valve timing disc is used to represent the position position of the piston inside inside the cylinder cylinder in a schematic manner. This helps to explain the piston p iston position more accurately. )? | ' a g e
0ig 7.&& =alve Timing Disc The portion bulged out is the power stroke region. This is the region corresponding to the region between the outer dead centre and the portion ust before the opening of exhaust. The disc rotates in the clockwise direction. The prescribed angle on the disc for the power stroke is &B:3. The disc has a radius of :.4 cm.
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6.6. THE WORKING OF THE CIRCUIT
0ig 7.&) The Circuit The supply voltage as shown in the figure is )/v dc. This high voltage is supplied to the voltage regulator. A &BBG resister is used before the voltage regulator inorder to reduce the high current to the circuit. The voltage regulator regulates the voltage and step down it to 4v dc$ since all the components in the circuit works only on 4v dc. This 4v is given to all the components in the circuit. The emitter is provided with a /8B ohm resistor and the collector is provided with a &BG resistor which reduces the voltage further. A voltage divider is used in order to divide the 4v to ).4v to provide it to the comparators. The transistor works as a switch. The emitter is forward biased and the collector is reversed biased. The emitter sends infrared radiations continuously and this is sensed by the sensor. Thus the circuit is short circuited. (ence low voltage is given to the comparator. #hen the power stroke region is reached the path gets cut off and as a result a high voltage is produced in the sensor circuit and this is given to the comparator. Comparator only provides the output when the input in the positive terminal is above 4v. Thus during the power stroke region the comparator is provided with a high voltage and thus it provides a high voltage at its output. This output is given to the transistor through a &G resistor. The transistor acts as a switch. !t conducts only when a high & | ' a g e
voltage is applied to it$ and when this high voltage reaches it conducts it to the 2) solenoid valve. The solenoid valve has three terminals namely &. 1efe 1efere renc ncee termi termina nall ). !nput nput ter termi mina nall . 9utp 9utput ut term termin inal al The input terminal is connected to the supply and the output terminal and the reference terminal are shorted. The high voltage ,4v is given to the shorted circuit and thus the valve opens and the pressuri"ed air is allowed to enter the cylinder of the engine. Thus the engine works.
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6.. THE CIRCUIT LAYOUT
0ig. 7.& The Circuit ayout This is the circuit layout used to implement our designed circuit to reality. This layout is obtained using the 'C< layout software. This is made by drawing this schematic diagram in a copper board and is placed in a solution of ferric chloride for &4 to )4 min.
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CHAPTER
THE PIPE SYSTEM The The pipe pipe syst system em is used used to conne connect ct the the comp compon onen ents ts invol involve ved d in the the pass passag agee of the the compressed air. !t is used to connect the cylinder to the solenoid valve and the solenoid valve to the cylinder head.
0ig. 8.& The 'ipe %ystem (ere polyurethane pipes are used of diameter of &)mm and length of &m. They are made of hard and flexible material so that they are able to pass the compressed air more efficiently and are highly flexible. These pipes are able to withstand high pressure and so are used to transport compressed air. They are perfectly suited to be inserted to the one touch male connector.
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.1. CONNECTORS Connectors are used to connect the pipes with the components used in this proect. The type of connector used is one touch male connector which has an internal hexagonal socket. The specification of the thread is <%'T 1&2) ,
0ig 8.) connectors
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CHAPTER !
PRESSURE GAUGE SYSTEM The pressure gauges are used to measure or display the pressure at the position at which the pressure gauge is installed. There are different ranges of the pressure gauges. B to &B bar pressure gauges are used in this proect. A t shaped female connector is used to install the pressure gauge in the system and an d it also holds the pressure gauge gaug e at position. The pressure gauge is connected to the inlet of the solenoid valve. This helps to measure the pressure inlet to the solenoid valve.
0ig :.& 'ressure +auge %ystem
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CHAPTER "
WORKING OF AIR DRIVEN ENGINE 9ur air engine works on the same principle of that of an internal combustion engine. The only difference between the two is that in an internal combustion engine5 the explosion of fuel in the combustion chamber produces the energy to move the piston$ while in an air engine the energy for moving piston is acuired from the supplied compressed air. The complete assembly of our air engine consists of slightly modified ic engine$ valve timing disc attached to the flywheel of the engine$ sensor controlled valve mechanism$ piping system$ gauge system$ air compressor and air tank.
0ig. ?.& #orking
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0ig. ?.) =alve Timing 0or the proper and continues working of the engine the timing with which the compressed air is supplied is of great importance. %o in order to make it precise we used sensor controlled valve mechanism. The valve timing disc is is made with utmost precision to precise operation of valve. 0or that the outer dead centre region ,9DC of the piston is found out and is marked on to the fixed valve timing disc.
0or starting5 the engine is cranked by the kicker. This will rotate the crankshaft along with the valve timing disk in the clockwise direction. During this rotation the 9DC region of the disc cuts the !1 beam first and followed by the E'9 region. #hen the !1 beam is first cut by 9DC region$ the circuit activates the solenoid valve by electric signal. At the moment the valve gets opened and allows the flow of compressed air into the cylinder from the tank through the piping system. The whole region from the point of 9DC to E'9 on the valve timing disk is opaue and does not allows the !1 beam through it. it. %o all all the the way way long long the the circ circui uitt main mainta tain inss the the sole solenoi noid d valv valvee open open by suppl supplyi ying ng a continuous supply of electric current to the valve. At the same time the compressed air from the tank continues to fill in the cylinder there by pushing the piston further towards the bottom dead centre,
valve there by closing the valve. This will prevent the valve from being open at the same time of E'95 increasing efficiency. #hen the disc rotates further$ the valve remains closed throughout the area from the E'9 to the 9DC as the !1 beam is closed. And this cycle continue.
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CHAPTER 1#
TESTING 1#.1. PURPOSE OF TESTING oad testing is the process of loading the engine for the purpose of calculating the maximum torue and brake power by a load testing apparatus.
1#.2. TESTING APPARATUS 0or load testing our air engine5 we made the testing apparatus our-self consisting of brake drum$ spring balance$ rope and holding frame.
0ig. &B.& brake drum The brake drum of our testing apparatus apparatus was made by slightly slightly modifying modifying the clutch disc of our engine itself itself and coupled coupled it to the crankshaft. crankshaft. The spring spring balance is held in place to the main frame through a hole drilled into it. The rope is then tied to the hook of the spring balance. The other end of the rope is circled over the brake drum by a single loop in clockwise clockwise direction. direction. The weight placing base is attached to the loose end of the rope. Extra care is taken in order to make sure that the spring balance$ the rope and the weights are in straight line.
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1#.3. TESTING PRINCIPLE
&B..&. <1AGE '9#E1
#here5 w& J weight added in kg$ w) J load shown in spring balance in kg$ > J speed in 1'6$ d J diameter of rope in mm$ D J diameter of brake drum in mm g J gravitational constant.
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&B..). %'EC!0!CAT!9>% 90 TE%T!>+ A''A1AT% Diameter of brake drum D J .&)m .&) m J&)Bmm Diameter of rope d J .B&)m J&)mm +ravitational constant J ?.:&
0ig. &B.) brake drum of our engine
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1#.4. TESTING PROCEDURE &. 6ade sure that all the the connecti connections ons were were made made correct correctly. ly. ). 6ade sure sure that that the valve valve of compres compression sion tank tank is in in closed closed position. position. . Then the tank tank is filled filled up to to the reuired reuired pressure pressure by running running the the compressor. compressor. /. The electri electrical cal circuit circuit is is turned turned on by by closing closing the the connection. connection. 4. 6ade 6ade sure sure that that the engi engine ne is in in no load load conditi condition. on. 7. Then the the valve of of the compres compressor sor tank tank is opened opened gradually gradually to the maximu maximum. m. 8. 0or the the engine to start start running running it is cranked cranked with with the help help of the the kicker. kicker. :. #hen #hen the engine starts starts runni running ng and gained gained speed5 no load load readings readings of pressur pressuree in
0ig &B. Testing
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WEIGH PRESSURE T 1 2
3
4
5
6
!
"
NO LOAD
344
413
456
4!4
513
533
545
563
5!!
.5
314
3!4
43#
45#
46
5#!
516
526
556
1
3##
363
412
44#
465
4!#
4!5
4"#
53#
1.5
21#
26!
3!1
4##
441
45"
46"
44
5#6
2
2#2
21#
34
3!5
425
45#
46#
465
45
2.5
312
332
35
42#
436
452
46#
3
3##
326
354
363
3!1
421
43!
1#.5. OBSERVATIONS AFTER TESTING Table. &B.&
1#.6. SAMPLE CALCULATIONS
$%&''(%& )* " +)% ),- 3 / 0)Torue
J ,w&-w)HK,DLd2)MHg J ,-B.& HK,B.&)LB.B&)2)MH?.:&
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<'
J ,)HNH/:27B HK,B.&)LB.B&)2)MH,-B.&H?.:& # J/4.:7 H B.&) H ).? H?.:& watts J &8).)) watts
1#.. PERFORMANCE CHARACTERISTICS
0ig &B./ speed versus pressure
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0ig &B.4 speed versus torue
0ig. &B.7 brake power versus pressure
!n Air Driven Engine$ the speed is bound to increase with increase in the inlet pressure. The speed versus versus torue characteris characteristics tics shows shows a negative negative linear variation. variation. The brake power is observed to increase with increase in the inlet pressure.
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CHAPTER 12
ADVANTAGES OF AIR DRIVEN ENGINE •
less costly and more effective
•
The air engine is an &'',%&& piston engine that uses compressed air as a source of energy.
•
S$0& , ,'*%(*, . The engine can be massively reduced in si"e
•
E)'7 * ),*), ),- %&$)% .
•
N %& 8)9)%- problem due to over loading. Air$ on its own$ is non-flammable.
•
L: ),()*(%& ),- ),*&,),& '*'
•
Comparatively the $&%)*, '* ' 0&''.
•
L/8* , :&/8* ),- &)'7 * 8),-0& . The engine runs on cold or warm air$ so can be
made of lower strength light weight material such as aluminium$ plastic$ low friction teflon or a combination •
Compressed-air tanks can be disposed of or %&70&- :*8 0&'' $00(*, than batteries.
•
Compressed-air engines are (,,'*%),&- +7 *8& -&/%)-)*, $%+0&' associated with current battery systems.
•
The )% *), )7 +& %&00&- more often and in less time than batteries can be recharged$ with re-filling rates comparable to liuid fuels.
•
L/8*&% ;&80&' cause less damage to roads
•
The price of filling air tanks is significantly 8&)$&% than petrol$ diesel or biofuel. !f electricity is cheap$ then compressing air will also be relatively cheap
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•
<( %&'$,'& ' )8&;&- .
CHAPTER 13
APPLICATIONS 13.1. DRIVE FOR CONVEYORS Air driven engines can be used as drives for different types of conveyors such as
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0ig &.& belt conveyor
13.2. =OB CLAMPING !n operations like carpentry ob clamping generally reuires low loading. Air Driven Engine can provide this low load clamping.
13.3. FLUID PUMPS Air Driven Engine can also be utili"ed for small displacement pumps of low pressure capacities.
13.4. AUTOMOBILES The usage of the Air Driven Engine is possible for automobiles as two wheelers and light motor vehicles.
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0ig. &.) air car
CHAPTER 14
CONCLUSION #e were able to successfully complete the design and fabrication of the Air Driven Engine.
The Air Driven Engine provides an effective method for power production and transmission. Even though its applications are limited currently$ further research could provide wider applications.
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CHAPTER 15
FUTURE SCOPE O
Design Design and fabric fabrication ation of a new new engine engine made of light light metal metal will will give give better better results. results.
O
sag sagee of compr compres esse sed d air air tank tankss for for stor storag agee and and suppl upply y will will give give it more more scop scopee in automobiles.
O
6uch like electrical electrical vehicles$ vehicles$ air air powered powered vehicles vehicles would would ultim ultimately ately be powered powered through through the electrical electrical grid. This makes it easier to focus on reducing pollution pollution from one source$ as opposed to the millions millions of vehicles on the road. Transporta Transportation tion of the fuel would not be reuired due to drawing power off the electrical grid. This presents significant cost benefits. 'ollution created during fuel transportation would be eliminated.
O
Compre Compresse ssed-a d-air ir vehicle vehicless operate operate to a ther thermod modynam ynamic ic process process as air cools cools down when 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.
O
>ew engin enginee designs designs55 as shown shown in fig &/.& &/.& shows shows the impro improved ved varian variants ts of the the air engine engine.. #ith these type of engines5 which is more efficient5 air powered automobiles could gain a bright scope in future.
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0ig. &/.& air engine variant
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