| dc.description.abstract | Natural gas accounts for 32 percent of the United States’ total energy consumption [1], and as emissions regulations become more stringent, the need to reduce harmful emissions produced by natural gas engines has become increasingly important. One solution is to burn air-fuel mixtures in open chamber spark ignition with very lean air-fuel ratios, which reduces oxides of nitrogen (NOx) emissions. However, this process dramatically increases carbon monoxide (CO) and hydrocarbon (HC) emissions. To combat harmful emission, a precombustion chamber (PCC) can be introduced into the system. A PCC is a small chamber, about 1 to 2 percent of the main chamber’s clearance volume, that ignites a near stoichiometric air-fuel mixture and ejects an explosive jet into the main chamber. As a result, approximately one million times greater ignition energy is released compared to a normal spark plug [2] [3] [4]. Combustion stabilizes and in-cylinder temperatures are reduced, which reduces CO, HC, and NOx emissions.
This thesis provides performance and emissions data on three PCCs supplied by Cooper Machinery Services on an Ajax E-565 natural gas engine. A spark-ignited precombustion chamber for engine bore sizes of 10.5 inches up to 13.25 inches was tested to obtain performance and emissions data. Two other PCCs, Eco-Jets, were tested for the first time on an Ajax E-565 engine to obtain performance and emissions data. The novel results were analyzed, and further research and design opportunities were provided with a goal to reduce overall emissions, improve combustion stability, and improve engine performance. | en |
