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Compressed Natural Gas (CNG) engine has proved itself to be worthy replacement for diesel in heavy commercial and passenger transport application all over the world. In India, infrastructure development of CNG distribution and stringent emission regulations have increased the interest shown by Original Equipment Manufacturers (OEM) to concentrate to development of CNG vehicles in every segment. Indian cities are fighting pollution due to high vehicle density and since contribution of light commercial vehicles in intra city application is significant, application of dedicated CNG vehicle has been made mandatory. This paper discusses the development of dedicated CNG engine using injection technology meeting the upcoming BS-IV norms. The primary modifications made are in the cylinder head, piston, intake and exhaust systems. The engine being developed for commercial application, the best in class fuel economy is of prime focus.

In recent years the Government of India has supported the use of Liquified Petrolium Gas (LPG) in public and private vehicles. One of the ways to reduce emission is use of alternative fuels. Among alternative fuels, LPG is one of the most promising mainly because of its low exhaust emissions. The papers about LPG used in three wheeler, cars for SI or CI converted to SI engines had been published extensively in the last two decades. The applications of LPG to bi-fuel or single fuel engines are tried widely at this time. But the extensive study of LPG for small SI single cylinder two stroke engine of three wheeler two stroke engine is not reported in depth. This paper describes development of bi-fuel (LPG/Gasoline) concept of a single air cooled 200 CC single cylinder two stroke engine for three wheeler application.

A duel fuel diesel engine is a diesel engine fitted with a dual fuel conversion kit to enable use of clean burning alternative fuel like compressed natural gas. Dual fuel engines have number of potential advantages like fuel flexibility, lower emissions, higher compression ratio, better efficiency and easy conversion of existing diesel engines without major hardware modifications. In view of energy depletion and environmental pollution, dual fuel technology has caught attention of researchers as a viable technology keeping in mind the increased availability of fuels like Compresed Natural Gas (CNG). It is an ecological friendly technology due to lower PM and smoke emissions and retains the efficiency of diesel combustion. Traditionally dual fuel technology has been popular for large engines like marine, locomotive and stationery engines. However its use for automotive engines has been limited in the past due to constraints of limited supply of alternative fuels.

Due to the well-known fact of higher thermal efficiency, diesel engines are more popular than any other fuelled prime movers. Because of this feature, the diesel engines are extensively used in almost all on road and off road applications. Power generation is another widespread application of the diesel engines. Over recent past years, stringent emission legislations have been imposed on reduction of emission parameters emitting from diesel engines. Central Pollution Control Board (CPCB) of India has proposed further reduction in emissions applicable from 2013, which are the most stringent limits in the world for this category of engines up to 75 kW. This paper deals with the strategies applied and experimentation details to meet the proposed CPCB Stage-II emission limits. The criticality increases exponentially for naturally aspirated versions. The experimental investigations are carried out on various capacities of 1.0 l to 3.25 l naturally aspirated diesel genset engines.

Small power diesel engines are most demanding product in Indian market for stationary applications like power genset, agricultural purpose etc. The upcoming 2013 CPCB emission norms for diesel genset engines below 19 kW power rating are the most stringent one in the world. There is a need not only to upgrade technologies pertinent to the latest emission norms but also to reduce the product cost. This paper presents various design strategies used to meet the desired engine performance and emission levels for development of a series of small power diesel genset engines having bore dia. ranging from 76 mm to 120 mm.

This paper is focused on the prediction of in-cylinder pressure, temperatures and engine-out NOx. One of the important factors influencing engine output parameters is the rate of heat release, which affects the in-cylinder pressure, temperature and engine out emissions. A single-zone model is formulated for prediction of heat release and in-cylinder pressure. Being a predictive model, this model does not required cylinder pressure as an input. Combustion pressure is predicted by modeling compression pressure, ignition delay, heat release, and heat loss. Required Sub-models have been obtained from the literatures. Fuel burning rate is predicted using Watson model. To retain the computational efficiency and better prediction accuracy a two-zone model has been formulated to predict NOx emissions. Flame temperatures are predicted by enthalpy balance. Thermal NO concentration is predicted by using basic Zeldovich mechanism.