刘俊龙^1,2，陈国强^1,2，张洋洋^1,2，韩美莹^1,2

1.内燃机可靠性国家重点实验室，山东 潍坊  261061；2.潍柴动力股份有限公司，山东 潍坊  261061

摘要：为优化柴油机的辅助制动性能，以某中型柴油机为研究对象，采用GT-Power软件搭建一维热力学仿真模型，分析制动型线和相位变化对发动机制动性能的影响，研究压缩释放（compression release，CR）制动排气门开启相位、排气再循环制动（brake gas recirculation，BGR）排气门开启相位、开启包角以及排气复位等参数变化对发动机制动升功率、进气质量流量和爆压的影响规律。结果表明：同时采用CR制动与BGR可使制动升功率增加约20%；存在CR制动排气门开启最佳相位使制动升功率最大；采用排气门开启复位时制动升功率增加。基于此规律对制动型线优化，优化后的制动型线可使发动机的制动升功率提高5.1 kW/L。

关键词：柴油机；压缩释放；排气再循环；制动性能

Abstract：To improve the braking performance of diesel engine, a medium-sized diesel engine is employed to investigate the influences of the brake lines and their phase on the braking performance of the engine. The effects of compression release, brake gas recirculation and exhaust valve closing timings-with and without reset are simulated by GT-Power. It could be found that compression release braking as well as exhaust recirculation braking can increase braking power by about 20%, and there is an optimal exhaust valve opening phase angle to maximize braking power. The use of exhaust valve opening reset will also increase the braking power. Based on the conclusions, the original brake line is further optimized and thus the brake power increased by 5.1 kW/L.

Keywords:diesel engine；compression release；exhaust gas recirculation；braking performance