Author : D. Srikanth, M.V.S. Murali Krishna, P. Usha Sri and M. Ravi Chandra

Conservation of fossil fuels is gaining momentum along with adapting alternative fuel technology methods for the researchers and manufacturers involved in combustion research. The concept of low heat rejection (LHR) engine is to minimize heat flow to the coolant by providing thermal resistance in the path of heat flow to the coolant and thus increase thermal efficiency. It has significant characteristics of higher operating temperature, maximum heat release, and ability to handle low calorific value fuel. Investigations were carried out to evaluate the performance of diesel engine with air gap insulated low heat rejection (LHR–3) engine consisting of air gap insulated piston with superni crown , air gap insulated liner with superni insert and ceramic coated cylinder head with neat diesel with varied air gap thickness and injection timing. Performance parameters of brake thermal efficiency, brake specific fuel consumption, exhaust gas temperature, coolant load and volumetric efficiency were determined at various values of brake power. The optimum air gap thickness was found to be 2.8 mm with LHR–3engine with diesel operation. LHR engine with neat diesel operation showed deteriorated performance at manufacturer’s recommended injection timing of 27o bTDC (before top dead center) and the performance improved marginally with advanced injection timing of 28.5o bTDC in comparison with conventional engine (CE) at 27obTDC.

Keywords: Conservation of diesel, conventional engine, LHR engine, Performance

Article published in International Journal of Current Engineering and Technology, Vol.7, No.4 (Aug-2017)