摘要:为解决传统涡轮增压发动机低转速增压不足和高转速排气能量未得到充分利用的问题,提出了可实现压气机和涡轮解耦的机电复合柔性增压系统。针对某重型柴油机建立了机电复合柔性增压系统仿真模型,计算分析了该系统对柴油机性能的影响规律及关键因素。研究表明:该系统在中高转速工况系统综合效率最高可提升2.66%,原因主要在于涡轮发电系统回收利用了废气能量;通过控制涡轮转速可实现全工况最佳涡轮效率,优化后涡轮效率最高可提升1.2%;提高电动压气机功率能显著提升柴油机低速转矩,1 100 r/min工况下转矩最大可提升24%,且系统综合效率和燃油消耗率均得到改善。 |
关键词: 机电复合柔性增压系统 柴油机 综合效率 转矩 |
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Study of the Effect of Flexible Electric Turbo-Compound Systemon Diesel Engine Performance |
Xu Kangjing,Deng Kangyao,Yang Mingyang,Liu Ying,Wu Xintao |
Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiaotong University,Shanghai 200240;State Key Laboratory of Turbocharging Technology of Diesel Engine,Tianjin 300400 |
Abstract:Aiming at solving the problems of conventional turbocharger such as lacking of boosting at low speed while exhaust energy surplusing at high speed,a flexible electric turbo-compound (F-ETC) system with compressor and turbine decoupling. Based on a heavy duty diesel engine, the simulation model of a F-ETC system was built,and the influence of the F-ETC system on diesel engine and key factors were analyzed. The research shows that the overall efficiency of the system can be improved at medium and high speed with a maximum increase of 2.66%,and main cause is that surplus waste gas energy is recovered by turbine power system. The best turbocharing efficiency, which is 1.2% higher after optimization, can be achieved by turbo speed controlling. The low-speed torque of diesel engine can be significantly increased with the increase of electric compressor. At 1 100 r/min,the maximum torque can be increased by 24%,and the system overall efficiency and BMEP can also be improved. |
Key words: F-ETC system diesel engine overall efficiency torque |