Analysis of expanded cycle andInternal EGR for LHR turbochargedDi diesel engines

Abstract

Increasing thermal efficiency in diesel engines through low heat newlinerejection concept is a feasible technique In LHR engines the high heat newlineevolution is achieved by insulating the combustion chamber surfaces and newlinecoolant side of the cylinder with partially stabilized zirconia coating of 05 newlinemm thickness and the effective utilization of this heat depends on the engine newlinedesign and operating conditions To make the LHR engines more suitable for newlineautomotive and stationary applications the extended expansion was newlineintroduced by modifying the inlet cam for late closing of intake valve through newlineMillers cycle for extended expansion Through the extended expansion newlineconcept the actual work done increases exhaust blowdown loss reduced and newlinethe thermal efficiency of the LHR engine is improved In LHR engines the newlineformation of nitric oxide is high to reduce the high levels of nitric oxide newlineemission; the internal EGR is incorporated with the engine cycle with newlinesecondary exhaust valve opening during suction stroke Modifications of gas newlineexchange with internal EGR resulted in decrease in nitric oxide emissions newlineIn this work the parametric studies were carried out both newlinetheoretically and experimentally with closer duration of each crank angle newlinedegree Thermodynamic properties were estimated by using the first law of newlinethermodynamics newline newline