Influence of rarefaction at inlet and overpressure at outlet on emissions of harmful substances with exhaust gases of internal combustion engines in the energy sector of agriculture

Abstract

This paper discusses the results of rig tests on the influence of inlet rarefaction and overpressure at the outlet on the level of emissions of harmful substances (CO, СхНу, NOx, solid particles) with exhaust gases (EG) of 6ЧН 15/18 (in Russian) diesel engine (D6-type) designed for use as power units in mobile and stationary diesel generators in agriculture. In the experiments, with the turbocharger disconnected, such adjustments of the gas distribution mechanism were realized which provided air discharge at the inlet from 0.98 to 4.9 kPa (from 100 to 500 mm Hg), and the excess pressure of the exhaust gas at the outlet from 3.43 to 13.73 kPa (from 350 to 1400 mm Hg). After that, the supercharger was switched on and the internal combustion engine was tested at steady-state modes, the exhaust gas was sampled, physico-chemical analysis of its composition, determination of particulate matter dispersion, and the technogenic load was calculated. The results of the study have shown that when the inlet rarefaction increases from 0.98 to 4.9 kPa, the exhaust gas smoke increases, NO_x emissions decrease 1.25 times, CO emissions decrease 1.25 times, and particulate matter and CxHy emissions increase 1.35 and 1.75 times, respectively. At the same time, the technogenic load decreases 1.24 times. When overpressure increases at the outlet from 3.43 to 13.73 kPa, except for CO, emissions of all harmful substances increase which leads to increase of technogenic load on the environment 1.29 times. The internal combustion engine of D6-type in a serial configuration does not provide achievement of all levels by emission standards of the Stage standards which require installation of additional technical means to reduce emissions of harmful substances (NOx, CO, particulate matter).