| Internal combustion engines are major contributors to the pollution of our atmosphere by emitting carbon monoxide (CO), nitrogen oxide (NOx ), particulate matters (PM) and other pollutants. Thus, governments and state agencies have implemented more stringent regulations and restrictions on the tail-pipe emissions of IC engines. As a result, alternative engine concepts such as Homogeneous Charge Compression Ignition (HCCI) engines have gained more attention from many researchers. HCCI engines have advantages such as higher thermal efficiency especially at part-load, lower operating temperature, and low NOx and PM emissions over conventional SI engines. However, HCCI engines may produce more unburned hydrocarbons and CO emissions. Most of the current research has focused on the use of natural gas as a fuel in HCCI engines. The objective of the present study is to investigate effects of addition of small amount of hydrogen to natural gas in a natural gas HCCI engine. The numerical simulations were carried out using CHEMKIN Suite from Reaction Design. (Abstract shortened by UMI.)... |
