Effect of elevated coolant temperature on the exhaust composition of piston internal - combustion engine

There is a tendency to increase the economic efficiency of engine operation and energy efficiency and reduce emissions of toxic combustion products. One way to reduce emissions of toxic components in exhaust gases is raising the coolant boiling point, which requires the simultaneous increase in pressure in the cooling system. Previous studies suggest that such a system can reduce the amount of toxic components in exhaust gases, particularly at low engine load when the engine exhaust temperature is too low to make effective catalytic action. The paper presents the model and experimental test stands to research the cooling system at an elevated temperature of the coolant. The speed and load characteristics of the standard cooling systems and pressure were presented. The research results were designed to determine the effect of elevated temperature in the cooling system on the composition of the gases. The characteristics of the external speed and load were performed with standard cooling systems and pressure. When performing velocity characteristics of the engine was loaded up in the whole range of engine speed from 1000 to 4000 rev/min, while the load characteristics were performed for different values of torque at constant speed in the range from 1500-4000 rpm. The results confirmed the benefits of increasing the temperature of the coolant. The presented characteristics that apply pressure cooling system reduces the amount of toxic components in exhaust gases, particularly at low engine load, in which the engine operates most often in urban conditions.