重型柴油机压缩释放式缸内制动气门升程优化

王任信¹，王菁¹，吴继闽¹，凌健²

1.广西玉柴机器股份有限公司技术研究院，广西 南宁  530000；

2.中汽研汽车检验中心(天津)有限公司，天津  300000

摘要：为提升某重型柴油机压缩释放式缸内制动系统的制动功率，建立柴油机一维热力学计算模型，通过尺寸链计算压缩释放式制动气门安全运行边界；将尺寸链计算与气门升程曲线设计提前融入到优化方案，在制动气门运动允许范围内对压缩释放和排气再循环2次制动气门升程规律的开启角和包角双变量进行试验设计(design of experiment,DoE)及仿真。仿真分析结果表明：压缩释放和排气再循环制动气门升程的开启角和包角优化后，发动机转速为1100~1900 r/min时的制动功率提升14.4%，每循环进气量提升9.4%;将尺寸链计算与气门升程曲线设计提前融入优化方案的试验设计过程，能够提高设计方案的可行性。该优化过程可为后续的缸内制动气门升程优化提供参考。

关键词：柴油机；压缩释放；缸内制动；尺寸链计算；开启角；包角；DoE

Valve lift optimization on the compress-release in-cylinder brake system for a heavy-duty diesel engine

WANG Renxin¹, WANG Jing¹, WU Jimin¹, LING Jian²

1.Technical Institute,Guangxi Yuchai Machinery Co., Ltd., Nanning 530000, China;

2. CATARC Automotive Test Center (Tianjin) Co., Ltd., Tianjin 300300, China

Abstract：In order to improve the braking power of the compression release in-cylinder brake system of a heavy-duty diesel engine, an 1D thermodynamic calculation model of the diesel engine is established, and the safe operation boundary of the compression release brake valve is calculated through the dimension chain. The dimension chain calculation and valve lift curve design are integrated into the optimization in advance. Within the allowable range of the brake valve movement, the experimental design and simulation of the opening angle and wrapping angle of the brake lift profiles of the compression release and exhaust recirculation are carried out. The simulation results show that the braking power increases by 14.4% and the air intake per cycle increases by 9.4% when the engine speed is 1100~1900 r/min after the optimization of the opening angle and wrapping angle of the compression release and EGR brake valve lift. Integrating dimension chain calculation and valve lift curve design into the experimental design process of the optimization in advance can improve the feasibility of the design scheme. The optimization process can provide a reference for the subsequent optimization of valve lift of in cylinder brake.

Keywords:diesel; compress-release ;in-cylinder brake; dimension chain calculation; opening angle;wrapping angle;DoE