A Investigation to Reduce the Thermal Losses ...

A Investigation to Reduce the Thermal Losses of CNG Fuelled Engine and Improving the Throttle Response

Author Name : Kaushal Kumar, Sanjay Chhalotare

ABSTRACT This study examines the measured and calculated response of an internal-combustion engine operated at 900, 1500 and 2000 rpm with no fresh-air jet and with fresh-air injection velocities of 1.5 and 2.5 m/s into the exhaust system. Recorded variables included engine and exhaust-gas temperatures, throttle-position sensor (TPS) reading and manifold absolute pressure (MAP). Calculated parameters included intake-air and exhaust-gas volumetric flow, exhaust velocity, air and fuel mass-flow rates, and thermal loss. Across the tested speeds, the 2.5 m/s jet case produced the largest calculated exhaust flow and exhaust velocity and the lowest reported engine temperature and thermal-loss values. At 2000 rpm, for example, exhaust flow increased from 0.5033 to 0.6539 m³/min and the calculated thermal-loss value decreased from 9.823 to 7.3436 kJ/s relative to the no-jet case. The results indicate a promising association between jet-assisted exhaust flow and the reported thermal indicators; however, emissions, brake power, fuel consumption and measurement uncertainty were not supplied. Consequently, improvements in combustion efficiency or pollutant emissions cannot be confirmed from these data alone.