Experimental Investigations on DI Diesel Engine with Different Combustion Chambers Insulation

Aim: The four-stroke single cylinder diesel engine’s performance with various low heat rejection (LHR) combustion chambers was determined Critical comparison was made for various configurations of the combustion chambers with neat diesel operation.
Design Parameters: Direct injection diesel engine with various configurations of the combustion chambers–Combustion chamber with air gap insulation and ceramic coating (LHR–3); air gap insulation (LHR–2); and ceramic coated combustion chamber (LHR–1) Injection pressure and timing.
Materials and Methods: Exhaust emissions and performance parameters and were evaluated at different values of brake mean effective pressure (BMEP) of the engine. Combustion parameters were evaluated at its peak load operation. Particulate emissions were determined by smoke opacity meter (AVL 437), while nitrogen oxide levels were noted by NOx Analyzer (Netel Chromatograph NOx Analyzer (VM 4000). Combustion characteristics of the engine were determined at peak load operation of the engine using TDC (top dead centre) encoder, miniature Piezo electric pressure transducer, and special p (pressure)–θ(crank angle) software package.
Brief Results: Deteriorated performance was shown by the engine with air gap insulated and ceramic coated (LHR–3) combustion chamber, when compared with engine with other configurations of the combustion chamber at recommended injection timing of 27° bTDC.(before top dead centre)
Conclusions: Engine with LHR–1, LHR–2 and LHR–3 combustion chambers with mineral diesel operation showed deteriorated performance at 27° bTDC and improved at optimum injection timings and with increased injection pressure.