2-Stroke Fuel Injected Petrol Engine

Supervised by:

Mr. Sumit Sharma

Assistant Professor

ASET, Noida

Group Members

7-MAE-1: Akshay Garg : A2305410024 Soumi Badyopadhyay : A2305410027 Vaibhav Gupta : A2305410048

7-MAE-2: Neeraj Kalra : A2305410099

Overview of The Project To introduce direct fuel injection in a 2-stroke petrol engine. Thereby:

Increasing the efficiency of the engine. Reducing the fuel consumption of the engine Reducing the unburned hydrocarbons emissions.

Description of Project: The two stroke engines which was majorly used for single cylinder two

wheelers are now expired from the market due its poor fuel efficiency and pollution.

Besides these drawbacks the two stroke engines have many advantages over fourstroke engines like mechanical effeciency of the two stroke engine is 1.3 times the four stroke engines since there is no valves, It is simple in construction and weight of the engine is comparabley less, manufacturing and maintanance cost is less, the parts to be lubricated is less.

Hence by elemenating the disdvantages specified above the two stroke engines could be brought back to the use and employed in the two wheelrs. This research work deals with the solution to those problems in two stroke engine.

By this low cost efficient two wheelers could be manufactured to adhering to the latest pollution norms. The fuel efficiency and low emission of the four stroke engine is due to fuel injection system. If this system is suitably employed in the two stroke engines these benefits could be achieved in low cost compared to the four stroke engines.

Implementation of this system will increase the fuel efficiency and reduce the emission.

 

INTRODUCTION Two-stroke engine is an internal combustion engine that

completes the process cycle in one revolution of the crank shaft (an up stroke and a down stroke of the piston, compared to twice that number for a four-stroke engine). This is accomplished by using the beginning of the compression stroke and the end of the combustion stroke to perform simultaneously the intake and exhaust (or scavenging) functions.

In this way two-stroke engines often provide strikingly high specific power, at least in a narrow range of rotations speeds. The functions of some or all of the valves required by a four-stroke engine are usually served in a two-stroke engine by ports that are opened and closed by the motion of the pistons, greatly reducing the number of moving parts

COMPARISON BETWEEN TWO STROKE AND FOUR STROKE ENGINE

1) Generally a two stroke engine is lighter and has less moving parts so loses less power through friction and inertia, Because 2 stroke engines fire every 2 strokes they can develop more power.

2) In the case of two-stroke engines, for every two strokes of the piston inside the cylinder, one power stroke is produced

3) In four-stroke engines, power is produced once during four strokes of the piston. For the same size engine, the power produced by the two-stroke engine is more that the four-stroke engine.

4) Since there are no valves in the two-stroke engine and only ports, they are cheaper and require less maintenance.

5) With two-stroke engines, the torque produced on the crankshaft is more uniform because the power is produced during every alternate stroke of the piston.

6) Mechanical efficiency is high since the moving parts is less 7) Starting is easy 8) The two-stroke engine does not operate with the same efficiency at

different speeds.

Temp., Pressure sensor, Crank Angle sensor sensor

3 phase stator

Proposed Design

Materials Price List

Sl No. Hardware Required Cost in Rs Status

1 Fuel Injector 2500

Already ordered

2 Injection Pump 5000

3 High Pressure Pump

35004 Low Pressure Pump

5 Sensors 5000 Not yet ordered

6 Battery 2000 ü

7 Fuel Tank 500

8 Fuel Filter 1000

9 Engine (60cc) 5000 ü

10 Servo motors 1000

û11 Connecting cables 1000

12 Micro-controller 3000 To be Programmed

13 Miscellaneous 2000

Total 31,500

Fabrication MethodologyFirst, location of fuel injector is to be at 45

degrees.We have already purchased a piston with extended

skirt to close the ports.We are then attaching the crank angle sensor

externally.Temperature and pressure sensor are to be placed

on the exhaust manifold.Then the sensors will be connected to a micro

controller, which will control the fuel injector.

OPERATIONPISTON FROM TDC TO BDC

The inlet port is closed and the air is subjected to crankcase compression.

The piston opens the exhaust port the exhaust gasses in the previous cycle combustion will leave the cylinder.

Then the transfer port is opened and the scavenging is done by the incoming air by this the remaining exhaust

gas is forced out by the incoming air.

PISTON FROM BDC TO TDC

• The piston close transfer port.The piston closes the exhaust. Now the

compression of the charge startsThe fuel is injected inside combustion

chamber immediately after the exhaust port is closed

Continued…The injection pressure is around 8O bars.The piston uncover the inlet port and the air

enter inside the crankcaseIgnition takes place just before the piston

reaches TDC and the fuel is burnt.

ADVANTAGES: Only air is used for scavenging so waste of air fuel mixture through the exhaust port is prevented.

Fuel is injected in high pressure so atomisation of the fuel is good and complete combustion will takes place.(injection pressure is around 80 bar)

FUEL INJECTION IN TWO STROKE ENGINE The fuel from the fuel tank is given to the fuel pump.

Then the pump pressurizes the fuel to around 80 bar pressure. Then the fuel is taken to the injector through the high pressure

line. Then the fuel injection starts at 730 after BDC The fuel injection ends by 780 after BDC

COMPONENTS-Hardware and SoftwareFuel injection pumpFuel injectorSensorsVirtual instrumentationBatteryBREAD BOARD

 

SENSORS Throttle Position Sensor- Throttle position sensor will give the position

of the throttle valve by which the control system is able to sense the requirement of the driver. Engine idling condition is also given by this system.

Speed Sensor- Speed sensor will give the engine rpm to the system this will help the system to determine the timing of injection and ignition.

Mass Flow Rate Sensor- mass flow rate sensor in placed in the inlet manifold. It will give the amount of fuel drawn into the cylinder per cycle. This will help the control system to determine the load on the engine.

Atmospheric Air Temperature Sensor- Atmospheric air temperature sensor will give temperature of the air in the inlet.

Inlet Pressure Sensor- inlet manifold pressure sensor is placed in the inlet manifold this will give the information about the suction created in the cylinder during the suction stroke.

Lambda Sensor- Lambda sensor is an oxygen sensor which will give the amount of oxygen in the exhaust gas. This will give the feedback of the combustion to the system. This intern will control the amount of air and fuel for the combustion.

VIRTUAL INSTRUMENTATION SYSTEM:

It is the control unit of the system, Virtual instrumentation is software which will interface the sensors and give the signals to the actuators according to the program loaded.

The entire system of operation is controlled by this system with the help of inputs from the sensors and the program loaded to it. It collects the various data from sensors like throttle position, inlet air pressure, mass flow rate of air, atmospheric air temperature, engine speed, load on engine, and control the entire operation of the engine.

It is a closed loop system since it will get the feedback from the lambda sensor placed in the exhaust manifold which will give the amount of oxygen present in the exhaust gas. Amount of oxygen present in the exhaust gas will indicate the incomplete combustion so with respect to the input from the lambda sensor control system will evaluate the fuel injection timing and amount of fuel to be injected.

PORT TIMING

Port Timing Diagram of Two Stroke GDI Engine

The inlet port is opened by the piston 450 to 550 before TDC position.

The inlet port is closed 450 to 550 after the TDC.The exhaust port is opened 650 to 750 before BDC. The exhaust port is closed 650 to 750 after the

BDC. The transfer port is opened 550 to 650 before BDC.The transfer port is closed 550 650 after TDC.The ignition takes place at 150 to 250 before TDC.The fuel injection starts at 700 to 750 after BDC.The fuel injection ends 750 to 800 after BDC

Advantages of The Design Through our design the fuel is injected at high pressure directly into the combustion

chamber, which is placed in the cylinder head. Only air is used for scavenging process. The injection of the fuel will begins just after the exhaust port is closed so the fuel is

not wasted. The injection of the fuel  is in high pressure so the atomisation of the fuel is good

and also enhances thorough mixing of fuel before burning  so the combustion will be complete.

Electronic engine management system in implemented so the entire engine operation is precisely controlled electronically.

ANALYSIS AND CALCULATIONS

DIMENSIONS CORE SIZE : 110*121mm^2

PORT SIZE: a) total length: 72mm outer diameter: 39mm b) inner step: 24 mm inner diameter: 22.5mm c) screw size : 2*6mm (as we have 2 screws)

BORE SIZE: 42.6mm

STROKE LENGTH: 42mm

PIN SIZE : pins 4 in number each having a size of 6mmPIN SIZE TOTAL LENGTH= 69mm+11mm=80mm( 4 pins we have) and (11mm end thread size).

PISTON : a) piston diameter: 42.5mm piston length: 46.5mm

MAX. TORQUE : 4.5Nm at 5500rpm MAX. POWER : 3.5bhp at 5000rpm

CALCULATIONSPISTON DISPLACEMENT = = bore*bore*3.14*stroke 4 = 42.6 * 42.6 * 3.14 * 42 cc 4 * 1000

= 59.83 cc

SWEPT VOLUME = bore* bore*12.8704*stroke

= 42.6*42.6*12.8704*42

= 980.98cc

CLEARANCE VOLUME=

= chamber volume(cc)+ deck volume + gasket volume + piston volume

= 59.9 + 3.8 + 11.4 + 65.96 = 141.06cc

COMPRESSION RATIO= = swept volume +

clearance volume clearance

volume = 980.98 + 141.06

141.06

= 7.96

MEAN EFFECTIVE PRESSURE (m.e.p) = horse power * 6500

Volume(in L) * Speed (rpm)

= 3.5 * 6500

0.0598 * 5000

= 75.95 bar

BRAKE POWER = 2 * 3.14 * N (speed in rpm) * Torque

60

= 2 * 3.14 * 5000 * 4.5 KW

60

= 2.355 KW

INDICATED POWER = mep* stroke length* area* no. of

strokes* no.of cylinders KW

60 * 1000

= 75.95 * 42 * 1625.97 * 2

60 * 1000

= 0.172 KW

MECHANICAL EFFICIENCY = BRAKE POWER

INDICATED POWER

= 2.355 = 13.62

0.172

CONCLUSIONThus implementing gasoline direct injection

system in two stroke petrol Engines along with the electronic engine management system we could achieve various advantages which will be competitive with the modern four stroke engine in all the ways like fuel efficiency, power developed and emission norms.

The ultimate aim of this project is to bring the two stroke use again with satisfying the latest social and environmental requirements.

REFERENCE:

IC Engines- V. GanesanAutomotive spark-ignited direct-injection

gasoline engine-F. Zhao, D.L. HarringtonSensors for Automotive Technology - J. MarekGasoline Fuel Injection System - L-Jetronic –

BoschAutomotive Control Systems - Lars Nielsen

THANK YOU