Analysis the optimum inlet air temperature for controlling homogeneous charge compression ignition (HCCI) engine

Abstract

Homogeneous charge compression ignition engine is promising replacement for conventional CI diesel engine with lower oxides of nitrogen (NOx) and smoke emissions and improves the thermal efficiency with consume less amount of fuel. In general, HCCI engine operates with lean air/fuel charge for all operating condition, and it makes the HCCI combustion more complex and difficult to control the start of ignition point. The inlet air temperature is the primary parameter for controlling the HCCI combustion. In this study, the HCCI engine was operated at different inlet air temperatures as 90°C, 100°C, 110°C, 120°C, 130°C, 140°C and 150°C respectively. From this study, it was observed that the level of NOx emission increased with increasing the inlet air temperature and smoke emission was reduced with increasing the inlet charge temperature. The inlet air temperature about 120°C showed maximum reduction of smoke emission about 15HSU at 60% load. Similarly, CO and HC were reduced with increasing the inlet air temperature. The specific fuel consumption of HCCI mode engine decreased with increasing the inlet air temperature and the power output of the engine increased with increasing the suction air temperature.