DOI 10.4010/2016.646 ISSN 2321 3361 © 2016 IJESC Research Article Volume 6 Issue No. 3 Fuel Vapour System for SI Engine Using Bubble Creation Method Balaprakash1, Ganesan.V2 UG Scholar1, Assistant Professor2 Department of Automobile Engineering Christ the King Engineering College, Karamadai, Coimbatore, Tamil Nadu, India [email protected], [email protected] Abstract: The aim of this paper is to obtain vapour from petrol and use this vapour to ignite the Engine. Here we have used bubble creation method for obtain the vapour from petrol. The fuel vapour produced is much better than the fuel mist. The performance and emission test were conducted between the normal carburetor and fuel vapour system. The emission test was conducted and the following results were obtained as CO 0.03% and HC 42 PPM. The performance test was conducted and the following results were obtained as the mileage was significantly increased than the normal carburetor values. Keywords: Fuel vapour, carburetor, control valves, vapouriser chamber I. INTRODUCTION: airflow and therefore, indirectly, the fuel flow. In In this system, the fuel is made as vapour by using automobile engines, fuel injection systems are used in most vapourised chamber. The vapourised chamber has the models, controlled by a central unit that adjusts the duration amount of fuel inside, which the hose is dipped into it to of time during which the injectors remain open to deliver suck the atmospheric air into the chamber, due to vaccum fuel into the air stream. As everyone knows, analogous creation inside the chamber. The vapourised chamber has a systems have been adopted on some high range motorcycle float chamber to keep up in constant fuel level. When the engines. atmospheric air flow into the fuel, the air gets vapourised and sent to the engine through an outlet hose in the chamber by means of vapourised fuel using vapourised chamber. II. COMPONENTS: Construction of this fuel vapour system is simple in which it requires less economy than other vapourising methods. The main components of this system are, 1) Carburetor 2) Vapouriser chamber 3) Control valves and throttle valve 4) Float chamber A. Carburetor: Otto cycle engines used to power both two and four stroke motorcycles are fed with fuel (normal gasoline, special gasoline’s for some competition needs or, in some uncommon cases, methyl and/or ethyl alcohol), which is sufficiently volatile and has ignition properties which allow it to be premixed with the combustion air before the combustion is initiated by the spark plug. On the other Figure 1: Carburetor Working hand, in Diesel cycle engines, the fuel is less volatile and has ignition properties which require that it be mixed with In most cases, however, carburetors are widely air only inside the combustion chamber, where the pressure used, where the fuel is introduced according to the vacuum and temperature conditions are such to induce natural generated on various systems of fuel jets. ignition. For this reason, the power delivery of diesel The carburetor is the basic functions: engines may be adjusted by fuel delivery alone, without the 1. To control the power delivered by the engine, need to control the airflow. In Otto cycle engines, when the adjusting the airflow inducted according to driver fuel is pre-mixed with the air, it is necessary to control the demand. International Journal of Engineering Science and Computing, March 2016 2770 http://ijesc.org/ 2. To meter the fuel flow into the inducted air stream, while keeping the air/fuel ratio in the optimum range over the engine's entire working range. 3. To homogenize the air and fuel mixture in order to make the ignition and combustion proceed properly. B. Vapourising chamber Figure 4: 3 Way Valve A ball valve is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball (called a "floating ball") to control flow through it. It is open when the ball's hole is in line with the flow and closed when it is pivoted 90-degrees by the valve handle. The handle lies flat in alignment with the flow when open, and is perpendicular to it when closed, making for easy visual confirmation of the valve's status. Ball valves are durable, performing well after many cycles, and reliable, closing securely even after long periods of disuse. These qualities make them an excellent choice for shutoff applications, where they are Figure 2: Vapourising Chamber often preferred to gates and globe valves, but they lack their fine control in throttling applications. The vaporising chamber made up of hard plastic. It consist’s of two poly vinyl chloride (pvc) pipes provided at The ball valve's ease of operation, repair, and the top of the vapourising chamber. versatility lend it to extensive industrial use, supporting pressures up to 1000 bar and temperatures up to 752 °F One of the pipe is dipped half of the fuel level (500 °C), depending on design and materials used. Sizes typically range from 0.2 to 48 inches (0.5 cm to 121 cm). Another pipe is placed without contact of the fuel Valve bodies are made of metal, plastic, or metal with a The process of vapourising chamber is to create ceramic; floating balls are often chrome plated for fuel vapour by using atmospheric air with the help of durability. One disadvantage of a ball valve is that they trap engine suction. At the time bubbles are created in the water in the center cavity while in the closed position. In vapourising chamber. the event of a freeze, the sides can crack due to expansion of ice forming. Some means of insulation or heat tape in C. Control valves. this situation will usually prevent damage. Another option for cold climates is the "freeze tolerant ball valve". This style of ball valve incorporates a freeze plug in the side so in the event of a freeze up, the freeze plug ruptures, (acts as a sacrificial disk), thus making for an easy repair. Now instead of replacing the whole valve, just screw in a new freeze plug. This is commonly called freeze plug technology. A ball valve should not be confused with a "ball-check valve", a type of check valve that uses a solid ball to prevent undesired backflow. Figure 3: 2 Way Valve International Journal of Engineering Science and Computing, March 2016 2771 http://ijesc.org/ D. Throttle valve automatically meters the fuel supply to the engine. However, this arrangement is found in many automatic liquid systems, for example the cistern of a toilet could be said to be a type of float chamber. E. Float chamber Figure 5: Throttle valve A throttle is the mechanism by which fluid flow is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (i.e., by the use of a throttle), but usually decreased. The term throttle has come to refer, informally and incorrectly, to any mechanism by which the power or speed of an engine is regulated. What is often termed a throttle (in an aviation context) is more correctly called a thrust lever, particularly for jet engine powered aircraft. For a steam engine, the steam valve that sets the engine speed/power is often known as a regulator. In a gasoline internal combustion engine, the throttle is a valve that directly regulates the amount of air entering the engine, indirectly controlling the charge (fuel + air) burned on each cycle due to the fuel-injector or carburetor maintaining a relatively Figure 6: Float Chamber constant fuel/air ratio. In a motor vehicle the control used by the driver to regulate power is sometimes called the A float chamber works by allowing liquid within throttle pedal, as it controls the throttle opening, although the chamber to lift a float which is linked to a valve which "accelerator pedal" is more accurate, since not all vehicles regulates the liquid intake. When the level is low, the float have throttles. A diesel engine does not have a throttle; its drops and opens the valve, allowing in liquid until the float power level is controlled by regulating the fuel flow into rises sufficiently to close off the valve again. This is the engine, thus "throttle" and "gas pedal" are both identical in principle to the ballcock valve. inaccurate terms when applied to a diesel engine. III. METHODOLOGY: The throttle is typically a butterfly valve. In a fuel- injected engine, the throttle valve is placed on the entrance of the intake manifold, or housed in the throttle body. In a carbureted engine, it is found in the carburetor. When a throttle is wide open, the intake manifold is usually at ambient atmospheric pressure. When the throttle is partially closed, a manifold vacuum develops as the intake drops below ambient pressure. Usually, the throttle valve is controlled with a throttle pedal or lever via a direct mechanical linkage. In vehicles with electronic throttle control, the manual throttle control sends a signal to the Engine Control Unit (ECU), which then directly controls Figure 7: Block Diagram of Fuel Vapour System the position of the throttle valve. This means that the WORKING operator does not have direct control over the throttle valve; During suction stroke the piston in the cylinder the ECU can finely control the valve in order to reduce moves from top dead centre to bottom dead centre. During emissions or maximize performance. this stroke the fuel vapour from the vapourising chamber A float chamber is a device for automatically regulating the sucked inside the cylinder through valves, and a vacuum is supply of a liquid to a system.