Possibility of reduction of the environmental impact of a diesel engine by means of changing the compression ratio

BACKGROUND: Agricultural production is a source of environmental pollution, therefore, solving the problem of reducing harmful emissions from diesel exhaust gases used in agriculture is important and relevant. Contrary to all forecasts, the use of environmentally friendly engines capable of competing with piston engines is limited in agricultural production. The study is aimed at solving one of the key problems of the present time — reducing the environmental impact from harmful emissions of diesel engines by means of changing the compression ratio. AIM: Search for ways to reduce the environmental impact of diesel engines by means of changing the compression ratio. METHODS: The experimental data were obtained during bench tests of the 4ChN 15/18 diesel engine according to the GOST 14846-2020. The test methods were in accordance with the GOST 10448-2014. According to the test program, diesel exhaust gases were selected, their composition and dispersion of solid particles were analyzed at compression ratios ε = 13.5...14.5 ...15.5 and the load curve at 1900 rpm. RESULTS: It was found that an increase in the compression ratio from 13.5 to 15.5 led to a decrease in emissions of solid particles (SP), hydrocarbons (CxHy) and carbon monoxide (CO) with exhaust gases, however, emissions of nitrogen oxides (NOx) increased through the entire load curve from Pe = 0 MPa to Pe = 1.24 MPa at 1900 rpm,. With a decrease of ε to 13.5, the environmental impact decreased by 1.15 times. CONCLUSION: The compression ratio can be considered as an adjustable parameter when solving problems of reducing emissions of nitrogen oxides from exhaust gases and has little effect on changes in SP and CO emissions. When the compression ratio is reduced from 14.5 to 13.5, the environmental impact is reduced by 1.15 times. To obtain the best results, it is recommended to use complex methods, for example, simultaneous changes of the compression ratio and catalytic neutralization.