MODREN INSTITUTE OF TECHNOLOGY & RESEARCH CENTRE VIPIN KUMAR YADAV

Overview of Presentation Introduction. Working Principle. Dual-Fuel Operation Factors Affecting Performance in Dual- Fuel Engine. Performance of Dual-Fuel Engine Advantages of Dual-Fuel Engine

Introduction to Dual Fuel Engine The dual-fuel engine works on diesel cycle. The gaseous fuel (the primary fuel) is added to the air inducted by the engine or supplied by the supercharger at a pressure slightly above the atmospheric pressure. This mixture of air and gaseous fuel is compressed in the cylinder just like air in normal diesel operation. At some point in the compression stroke, near top dead center, a small charge of liquid fuel called pilot fuel (or the secondary fuel) is injected through a conventional diesel fuel system. This pilot acts as a source of ignition the gas-air mixture in the vicinity of the injected spray ignites at a number of flame-fronts. Thus combustion stars smoothly and rapidly..

In CI engine, gaseous fuel (secondary fuel) is inducted and compressed in the engine cylinder with air, and a small quantity of diesel ( Pilot fuel- primary fuel) is injected through the conventional diesel fuel system to ignite the mixture What is DUAL FUEL ENGINE?

Why Dual fuel engine required ? The shortage of liquid fuel and the realization that gaseous fuels are far cheaper than liquid fuels have led to attention on dual-fuel engine. natural gas available to most of part of the world at rates cheaper than liquid fuels

THE WORKING PRINCIPLE Dual fuel Engine Working

Dual-Fuel Operation  Dual-fuel operation is achieved by the burning of both a gaseous fuel and diesel at the same time in a CI engine  Injection of small amount of diesel fuel can be used as an ignition source

FACTORS AFFECTING COMBUSTION IN A DUAL-FUEL ENGINE 1. Pilot fuel quantity 2. Injection Timing. 3. Cetane Number of Pilot Fuel. 4. Inlet Temperature. 5. Gaseous Fuels. 6. Effect of Throttling. 7. Mixture Strength

KNOCK AND ITS CONTROL IN DUAL- FUEL ENGINE NATURE OF KNOCK: - The phenomenon of knock in a dual-fuel engine is of the nature of auto ignition of gaseous mixture in the neighborhood of injected spray. KNOCK IN DUAL-FUEL ENGINE CONTROLLED BY ANY OF THE FOOLOWING METHODS :- Excess supply of air. Use of cold combustion air. Increased cooling of piston. Reducing the pressure of the gaseous fuel.

Advantage of Dual- fuel Engine The dual fuel engine has the following advantages: The gas burns without leaving any residue - exhaust is clean – less air pollution. The clean combustion results in reduced wear of the engine parts and reduced consumption of lubricating oil. The lubricating oil change periods are also increased as the maximum pressure in cylinder are less than those for a diesel engine, thereby reducing the blow-by past piston. This reduces the contamination of the lube oil. Lower initial cost and lower operating costs than a dedicated natural gas engine Better fuel economy than a dedicated natural gas engine Lower maintenance costs than a dedicated natural gas engine

CONCLUSION  The ignition delay in gas-fueled diesel engines of the dual-fuel type depends strongly on both the quantity and quality of the pilot fuel used.  Dual-fuel engine performance is improved with the employment of high cetane number pilots.  For stationary application, diesel substitution of 70% is possible by using dual fuel engine which is quite considerable and also economical