DEPARTMENT OF MECHANICAL ENGG: PCET BELTHANGADY

DEPARTMENT OF MECHANICAL ENGG:PCET BELTHANGADYA PRESENTATION OF SEMINAR ON TRANSONIC ENGINES SAJU JOHN VIII SEM MECHANICALUSN: 4PR10ME021Presented by:PCET ,BelthangadyTRANSONIC ENGINESPCET ,BelthangadyUnder The Guidance ofDr. Chandra Rao Madane B.E, M Tech, Ph.D, PGDMM, LMISTE, FIEPrincipal Internal combustion engines play a vital role in our day to day life in many ways. The two terms which are highly associated with an internal combustion engine are , Efficiency and economyEfficiency, which is simply defined by ratio of output to input . economy which is highly considered in automobile sector defined by the distance that can be travelled by the automobile by giving unit amount of fuel, expressed in kilometers per liter(km/l). INTRODUCTIONPCET ,Belthangady For an SI engine where a spark plug is used for igniting the charge has lesser efficiency than a CI engine where fuel is injected by a fuel injector due to the change in compression ratio. As the times goes on there introduced many technologies for increasing the efficiency and economy of ac IC engine, particularly in SI engines. The rapid change occurs in automobile industry as it is growing than other sectors. Some of these technologies are. Both are important for an internal combustion engine, used in automobilesPCET ,Belhangady Laser treatment of piston surface Advanced swirl flow induction technology (ASFS) Advanced tumble flow induction technology (ATFi) Gasoline direct injection (GDI) Programmable fuel injection (PGM-fi ) Digital twin spark ignition (DTS-I ) Digital twin spark swirl ignition (DTS-si ) Multi point fuel injection (MPFi) Laser fired engines Out of which the latest technology is transonic combustion technology (TSC), which is developed by the transonic combustion in corporation. In TSC the fuel is directly injected to cylinder in supercritical condition PCET ,Belthangady Ignition system of an SI engine is used to ignite the fuel air mixture (charge). It mainly consists of a spark plug which is operated at high voltage 20000-30000 V. The spark plug consists of two electrodes which are separated at a small distance (generally 0.1 mm). As the piston compresses the charge then a high voltage is passed between the electrodes and a spark generates between the electrodes, as the gap is very small which cause the combustion IGNITION SYSTEMSPCET ,Belthangady As above explained conventional spark ignition engines uses a spark plug and mostly the systems are followed by battery ignition or the magneto ignition. The spark is produced a bit earlier than when piston reaches Top Dead Centre (TDC). The conventional spark ignition engines are widely used now days in light motor vehicles and especially in motorcycles

CONVENTIONAL SPARK IGNITION ENGINESPCET ,BelthangadyLower thermal efficiency (20-35%) under normal conditions.Incomplete combustion.Knocking or Detonation.High exhaust emissions of (CO2 & NO2).Lead, this is used as an anti-knocking agent is extremely toxic to the environment.

LIMITATIONS OF CONVENTIONAL SPARK ENGINESPCET ,BelthangadyThe Transonic Combustion system (TSC) is a new combustion process for the gasoline internal combustion engine. The TSCcombustion process utilizes direct injection of fuel into the cylinder as a supercritical fluid based on the patented concept of injection-ignition. Supercritical fuel promotes rapid mixing with the contents of the cylinder which, after a short delay, results in spontaneous ignition at multiple locations. Multiple ignition sites and rapid combustion combine to result in optimum heat release and high cycle efficiency

TRANSONIC COMBUSTION TECHNOLOGY(SUPERCRITICAL COMBUSTION TECHNOLOGY)

PCET ,Belthangady TSCbrings together the injection and ignition processes to become Injection-Ignition.TSChas inherently short combustion delay and rapid combustion that result in heat release phasing for optimal efficiency. A characteristic of the TSCcombustion process is that injection of the fuel is delayed to the extent that the heat release predominantly takes place after TDC of the engine power stroke. In order to achieve this, the combustion process must have rapid air-fuel mixing, followed by a short delay period and combustion. Such characteristics can be achieved by injecting the fuel in the form of a supercritical fluid. Due to the supercritical conditions, gasoline ignites automatically like in diesel engines.Direct injection of fuel in the supercritical state enables significant fuel efficiency improvements to be achieved. It results in efficiencies that are equal to or better than todays Diesel engines

PCET ,Belthangady A supercritical fluid is any substance at a temperature and pressure above its critical point; it is not a solid, liquid or a gas. Generally supercritical fluids have properties between those of a gas and a liquid. Supercritical fluids also have other unique properties such as having no surface tension, the ability to solvate other liquids and solids. Supercritical fluids possess rapid mass transfer properties with diffusion coefficients more than ten times that of a liquid near the critical point. The density ranges between one third and two thirds of that of the corresponding fluid and varies significantly with temperature and pressure.SUPERCRITICAL FLUID

CRITICAL TEMPERATURE (TC) The maximum temperature at which a gas can be converted into a liquid by an increase in pressure. CRITICAL PRESSURE (PC) The minimum pressure which would suffice to liquefy a substance at its critical temperature.CRITICAL POINT The characteristic temperature (Tc) and pressure (Pc) above which a gas cannot be liquefied.PCET ,Belthangady HIGH PRESSURE PUMP CATALYTIC CONVERTERHEAT EXCHANGERSUPERCRITICAL FUEL INJECTOR

COMPONENTS OF TRANSONIC ENGINE

PCET ,BelthangadyHIGH PRESSURE PUMP

It pressurizes the gasoline up to 42-300 bars.It supplies the high pressurized gasoline to the catalytic converter The high pressure pump is used to increase the pressure of gasoline above its critical pressure. PCET ,Belthangady CATALYTIC CONVERTER

Metal-oxide catalyst that breaks fuel molecules down into simpler hydrocarbon chains. Catalytic activity that is two to three times of magnitude faster than the purely liquid form of the substance. Catalytic actions on the fuels reduce the amount of CO in exhaust emission.It oxidizes the fuel before the combustion by adding oxidizers like ethanol.

PCET ,BelthangadyHEAT EXCHANGER

The heat exchanger increases the temperature of the gasoline above its critical temperature (280-300C). It transfers heat from exhaust gaseous to the high pressure gasoline. Thus we can use the heat energy of exhaust gaseous SUPERCRITICAL INJECTORS

The Precision, high-speed injector whose resistance-heated pin places the fuel in a supercritical state as it enters the cylinder. Timing of fuel injection is controlled by an Electronic Controlling Unit (ECU). It accurately measures the amount of fuel according to the load conditions which is injected to the combustion chamber The compression ratio for the transonic engine is 13.5:1

OPERATION In super critical injection the fuel is readily mixed with the air than normal injection. The rapid mixing of the fuel enables the engine to derive maximum efficiency than in normal injection. The rapid mixing and multiple combustion sites are the reasons of the greater efficiency of transonic engines than in diesel engines

SUPERCRITICAL INJECTION VS NORMAL INJECTIONPCET ,BelthangadyThe efficiency of gasoline engine can be increased up to 50 to 70%.TSC decreases the amount of fuel needed to propel a vehicle. Like diesel engine, theTransonic Combustion technology operates in gasoline engine without needing a spark plug.Transonic injection is being developed for use with gasoline engines at present, but will also be compatible with advanced low carbon footprint bio-fuels in the future. Convenient use of exhaust gas temperature.

ADVANTAGES OF TRANSONIC ENGINESPCET ,Belthangady This technology enables the use of low octane number fuels in gasoline engines. Considerable reduction in exhaust emissions. TSC technology puts it into a supercritical state that allows for very fast and clean combustion.LIMITATIONS OF TRANSONIC ENGINES Manufacturing cost is high Injectors must be made carefullyPCET ,Belthangady Super critical combustion in diesel engine is achieved by heating diesel above 300C and pressurizing it above 100 bar which is the critical temperature and pressure of diesel fuel respectively. Fuel is partially oxidized by coating the fuel lines with catalytic materials like nickel & molybdenum. Oxygen will be supplied for this oxidation process by adding ethanol (2%) with diesel. SC combustion in diesel engine gives a thermal efficiency of 75-85%

SUPERCRITICAL COMBUSTION IN DIESEL ENGINEPCET ,Belthangady The thermal efficiency of an IC engine depends upon compression ratio, quality of fuel etc. Transonic combustion technology is the latest technology used to improve the thermal efficiency of IC engine. It injects the fuel into the combustion chamber in supercritical stage. TSC gives rapid combustion & multiple combustion sites, which improve the efficiency significantly. This technology can increase the economy of an IC engine. TSC reduces the exhaust emissions

CONCLUSION

PCET ,BelthangadyTHANKYOUPCET ,Belthangady