Визначення впливу на показники дизеля ЯМЗ-238 зміни конструктивних параметрів деталей циліндро-поршневої групи

Abstract

Significant effect to enhance technical, economic and environmental performance of diesel can be achieved by changing the design parameters of the cylinder- piston group , such as changing the diameter of the piston and its pace while maintaining the volume liter diesel. The calculations were performed using computer codes "Diesel -RK." As the object of the research is the diesel engine JMZ -238. Analysis of the dependence of the rated power Ne ratio of the diameter of the piston to move its diesel engine JMZ-238 shows that the reduction of stroke can improve the nominal capacity of diesel. Increasing the ratio of the diameter of the piston to its pace of 0,73 to 1,16 rated power output increased from 159,7 kW to 169,0 kW (5,8 %). The character of the maximum torque of the ratio of the diameter of the piston to its gait similar dependence of rated power , an increase of 837,7 Mg Nm to 886,3 Nm (5,8 %). Increasing the diameter of the piston improves mixture formation and combustion of the fuel mixture during the work pace , resulting in improved fuel efficiency of diesel. Increasing the ratio of the diameter of the piston to its pace of 0,73 to 1,16 effective specific fuel consumption decreases with 242,87 gr/(kWh) to 232,52 gr/(kWh ) (at 4,45 %). Increasing the ratio of the diameter of the piston to its pace of 0.73 to 0.93 are increasing the concentration of nitric oxide - 1235,1 mln-1 до 1574,5 mln-1 (27,5 %), a further increase in the ratio of the diameter of the piston to its pace of 0,93 to 1,16 leads to a decrease in the concentration of nitric oxide to the original value 1235,1 mln-1. Improving the process of mixing and combustion of the fuel mixture when increasing the ratio of the diameter of the piston to its gait from 0,73 to 1,16 leads to a reduction in emissions of particulate matter from 0,1708 gr/(kWh) 0,1045 gr/(kWh ) that almost 63,5 %. It is thus possible to conclude that increasing the ratio of the diameter of the piston to its gait preserving liter diesel engine performance may improve the technical, economic and environmental performance of diesel, but increase its overall size and weight , respectively.