Some effects of applying a new type of pistons for SU12-U diesel engine

In the task of research and development of internal combustion engines, the strong emphasis is placed on reducing emissions of harmful substances in exhaust gases, which include carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM, PN); while maintaining a high engine performance and, above all, adequate: power, fuel consumption, noise. One of the possibilities to reduce emissions of HC and engine working noise is to reduce the clearance between the piston and the cylinder liner. This is possible only, when the permanent deformations of the piston are reduced, which result from rapid piston temperature changes (thermal shocks). The newly developed composite aluminum alloy is characterized by high strength parameters and low dimensional hysteresis during repeated heating and cooling. The S12-U engine pistons are made of this material, and they had a slightly larger nominal diameter than the standard pistons. They were then mounted in the engine. The engine was tested on a test stand with the modern, accurate measuring equipment. Test results show, that the HC and CO content in the exhaust gas has been reduced, exhaust gas blowby to the crankcase declined, smoke emission was reduced and engine lubricating oil consumption was also reduced. Analysis of test results indicates that this has been achieved, mainly by reducing the clearances between the piston and the cylinder. The article provides detailed test results, mainly in the form of charts, on which one can compare the results, achieved by the engine with new material pistons with results of the same engine, but with the standard pistons.

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Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę.