Laboratory Evaluations of Controlled Combustion Quenching and Stratified Exhaust Gas Injection for NOx Control on a Four-Stroke Reciprocating Engine. Topical Report May 1987-December 1988

摘要

The report describes laboratory evaluations of Controlled Combustion Quenching (CCQ) and Stratified Exhaust Gas Injection (SEGI), two new proposed techniques for NOx control in natural gas piston engines. With CCQ a quenching fluid is injected into the combustion chamber during the combustion process. CCQ showed NOx reductions of 60 to 85 percent, with relatively small penalties in fuel consumption (less than 8 percent) and other emissions. Another potential advantage of CCQ is that, unlike with conventional water injection, there seemed to be very little contamination of the lubricating oil. This fact suggests that CCQ may be applicable without causing engine durability degradation, such as has been feared for conventional water injection. Engine tests of stratified exhaust gas injection were not so promising in that, for a given flow rate of exhaust gas the stratified exhaust gas gave only half as much reduction in NOx as homogeneous exhaust gas recirculation. However, it is believed that the exhaust gas stratification was not optimally configured; that is, the exhaust gas cloud was located too far from the spark plug.