DEVELOPMENT OF RELIABLE, COST EFFECTIVE, LOW EMISSIONS SOLUTION (emPact) FOR RICH BURN NATURAL GAS ENGINES

摘要

The common perception shared by many field operators of rich burn air-fuel ratio controllers is that most cannot maintain emissions over a period of time, and those that can are typically very difficult to set up correctly. As such, many have lowered their expectations and simply choose a system that is easy to adjust when it is time to tune the system to pass their periodic emissions tests.By optimizing a rich-burn engine, an enhanced A/F controller, and a three-way catalyst (TWC), low emissions levels can not only be achieved, but also maintained even with changes in ambient conditions, fuel quality, and engine operating conditions such as speed and load. By using a closed-loop control system with post-catalyst O2 sensing, the system can adjust itself automatically as speed, load, fuel and ambient conditions change, reducing or eliminating the need for frequent manual adjustment by service technicians to maintain emission levels below 0.15 g/bhp-hr Nox and 0.30 g/bhp-hr CO. This paper presents a high-level overview of the emPact emission control system developed for a family of VHP engines and discusses the results from engine demonstration tests.