Influences of fuel sulfur content on diesel engine emission characteristics under varying temperature and humidity of inlet air

Abstract

Abstract The influences of the sulfur content of diesel oils on the emission characteristics of a diesel engine were systematically investigated in this study. The temperature and humidity of the inlet air, engine output torque, speed were also varied accordingly. The sulfur content was ranged from 0.3 to 0.85 wt% while engine output torque from 0 to 10 kg‐m, and speed from 1000 to 2000 rpm. The intake air temperature and relative humidity were set at 20 °C & 40 °C and 50%RH & 90%RH, respectively. A four‐cylinder diesel engine with a displacement volume of 3856 cc associated with a computerized engine data acquisition system was employed to observe and measure the engine performance under varying operating conditions. The temperature and humidity of intake air were adjusted by an inlet‐air temperature / humidity conditioning system. A mechanically stirring machine was used to mix the diesel fuel oil and sulfur compound homogeneously. This study shows that the increase of the sulfur content would enhance the formation of SO2 and CO. In addition, higher temperature and humidity of the inlet air would result in considerable reduction of the NOx concentration while promotion of the CO formation.