Influence of Wear on Precision Pair Components in Modern Fuel Injectors on the Operating and Environmental Performance of a Compression-Ignition Engine

The paper discusses issues related to wear phenomena occurring in modern compression-ignition engine fuel supply equipment. The paper examines how non-efficient injectors affect the operating and environmental performance of a common-rail diesel engine. Engine and laboratory tests were carried out. During the engine tests, power, torque, specific fuel consumption (SFC) and environmental parameters were measured on a bench for the engine running on non-efficient and efficient fuel injectors. Wear of injectors resulted in a decrease in engine power of up to 9% and a decrease in engine torque of up to 2%. In contrast, SFC increased for the worn injectors by more than 9%. The non-efficient injectors were then examined on an STPiW-3 test bench with a thermal imaging camera to determine their degree of wear. They were then disassembled into their component parts and examined with a stereoscopic and an electron microscope. The examinations showed that there was contamination inside the fuel injectors tested, both from outside and generated by the high-pressure pump. It is discussed how the inadequacies of the injection apparatus affect the combustion process of the combustible mixture in the cylinder headspace and the overall operation of the engine.