分会场

高效清洁燃烧

摘要

To explore higher thermal efficiency of jet ignition natural engine, two efficiency improvement methods, increasing compression ratio (CR) and applying thermal barrier coating (TBC) were compared in the engine. The CR was increased to 17 by changing the shape of the piston, and TBC was spray onto the surface of piston. To further investigate the combustion and emission characteristics using the two methods, EGR was introduced. In the study of lean burn with air dilution, the results showed that both high CR and TBC improved the indicated thermal efficiency by 0.9% when compared with that of original engine. NOx and CO emissions increased for both measures, whereas THC emission decreased, especially, under leaner and high load conditions. In the comparison of the two methods, less NOx emission was observed using TBC, CO and THC emission were comparable. When EGR was further introduced, the highest ITE of 45.2% was achieved by TBC, whereas this was 43% for high CR method. Considering the overall performances, TBC was better choice for the jet ignition engine. Moreover, through the emission comparison before and after the three way catalyst (TWC), CO and THC emission can be oxidized effectively, whereas NOx conversion efficiency was low and even negative. Considering the extremely low NOx emission with leaner combustion (λ>1.6), the in-cylinder purification for NOx combined with a catalyst handling CO and THC was proposed for the development of jet ignition engine.

关键词

jet ignition, high compression ratio, low thermal conductivity, natural gas engine,

电子U盘全文仅限大会已缴费参会代表下载。

您还没有登录，请您先 点击这里登录