Taguchi method for investigation of the effect of TBC coatings on NiCr bond-coated diesel engine on exhaust gas emissions

Abstract

The NiCr bond coated piston and valve surfaces were coated with Cr2O3, Cr2O3 + 50% Al2O3, Cr2O3 + 75% Al2O3 powders by thermal barrier coating (TBC). The influence of the coating layers on CO, CO2, HC and NOx was examined both statistically and experimentally. The statistical investigation was carried out by using Taguchi analysis. According to the experimental test results obtained at different engine speeds, the sample with the highest CO2 value was found at 2600 rpm in the Cr2O3 + 75% Al2O3 coated diesel engine and the sample with the lowest CO value was found at 2600 rpm in the Cr2O3 + 75% Al2O3 coated diesel engine. Also, the sample with the lowest NOx value was found at 1400 rpm in the standard diesel engine and the sample with the lowest HC value was found at 2600 rpm in the Cr2O3 + 75% Al2O3 coated diesel engine. Experimental results were analyzed by Taguchi optimization method according to L16 (42) orthogonal array. According to the statistical results obtained from ANOVA test, factor levels affecting the exhaust emission values best ​​were found. In general, better emission values ​​have been determined in diesel engines with bond coated ceramic layers.