| 摘要:以某型6缸低速二冲程柴油机为研究对象，建立GT-POWER一维仿真模型，研究高、低压EGR系统对柴油机性能及排放的影响。研究结果表明:随着EGR率的上升，高压EGR系统中压气机运行点从中心高效区向低效区和流量减小的方向移动，而低压EGR系统的流量和压比变化较小；高压EGR系统缸内压力始终低于低压EGR系统，在低负荷时，导致燃烧速度和放热率峰值低于低压EGR系统；燃油消耗率随着EGR率的增加呈上升趋势，当EGR率增加到一定程度时燃油消耗率上升更明显，并且高压EGR系统燃油消耗率明显高于低压EGR；两种EGR系统都能降低NOx排放，但相同EGR率时，高压EGR系统NOx减排效果更好。 |
| 关键词: 低速二冲程柴油机 EGR NOx 性能 |
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| Study on Effects of High and Low Pressure EGRs on thePerformance and Emissions of Low Speed Diesel Engines |
| Li Shuran,Wang Dawei,Shi Lei,Deng Kangyao,Gui Yong |
| Key Laboratory for Power Machinery & Engineering of Ministry of Education，Shanghai Jiao Tong University，Shanghai 200240;Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration CISSE，Shanghai 200240;China Shipbuilding Power Engineering Institute Company Limited, Shanghai 201206 |
| Abstract:Based on a 6-cylinder low-speed two-stroke diesel engine, a one-dimensional simulation model was established with GT-POWER to study the influence of high pressure and low pressure exhaust gas recirculation(EGR) system on the performance and emissions of diesel engines. The results show that as EGR rate increases, the HP-EGR makes turbocharger working area move from high-efficient zone to low-efficient zone and less fresh air flow area, while the LP-EGR has small change on the flow and pressure ratio; the cylinder pressure of HP-EGR is always lower than that of LP-EGR at low load, combustion speed and peak of heat release rate are lower than that of LP-EGR; BSFC increases with EGR rate rising, and when the EGR rate increases to a certain level, the BSFC rises more obviously, and the BSFC of HP-EGR system is obviously higher than that of low pressure EGR; both EGR systems can reduce the NOx emissions, but the HP-EGR system has a better effect on the NOx emissions reduction with the same EGR rate. |
| Key words: low-speed two-stroke diesel engine exhaust gas recirculation(EGR) NOx performance |
