某MPC涡轮增压柴油机排温均匀性分析及优化设计
孙坤,孙永亮,李德华,颜鲁,张方方,孙放
潍柴动力股份有限公司 大缸径发动机研究院,山东 潍坊 261205
摘要:为提高某8缸直列模件式脉冲转换器(modular pulse converter,MPC)涡轮增压柴油机各缸排温均匀性,采用GT-Power仿真软件,搭建整机热力学仿真模型,对比额定工况下各缸的循环进气量、进气和排气道压力波、扫气压差,分析各缸扫气压差不均的影响因素。提出优化MPC歧管倾角、MPC总管直径、气门叠开角、发火顺序4项优化措施。仿真结果表明:优化MPC总管直径、气门叠开角、发火顺序可显著提高各缸排温均匀性,MPC歧管倾角对各缸排温均匀性影响较小。对不同MPC歧管倾角、不同MPC总管直径的柴油机进行台架试验验证。试验结果表明,歧管倾角对各缸排温均匀性影响甚微;将MPC总管直径缩减至原直径的57%,排温标准差由43 ℃降至30 ℃,排温均匀性得到显著提高。
关键词:柴油机;MPC;涡轮增压;GT-Power;排温均匀性
Uniformity analysis and optimization design of exhaust temperature of MPC turbocharged diesel engine
SUN Kun, SUN Yongliang, LI Dehua, YAN Lu, ZHANG Fangfang, SUN Fang
Large Bore Engine Research Institute,Weichai Power Co., Ltd., Weifang 261205, China
Abstract:In order to improve the exhaust temperature uniformity of an 8-cylinder in-line modular pulse converter (MPC) turbocharged diesel engine, a thermodynamic simulation model is built with the help of the simulation software GT-Power, referring to the three-dimensional structure of the whole machine, and the circulating intake air volume, intake and exhaust pressure waves, and scavenging pressure difference of each cylinder under rated conditions are compared, and the factors that caused the uneven scavenging pressure difference of each cylinder are analyzed. Four optimization are put forward: MPC manifold inclination, MPC manifold diameter, valve overlap angle and firing sequence. The simulation results show that the optimization of MPC manifold diameter, valve overlap angle and firing sequence can significantly improve the exhaust temperature uniformity of each cylinder, and the MPC manifold inclination has little effect on the exhaust temperature uniformity of each cylinder. Bench tests on diesel engine with different MPC manifold angles and different MPC header diameters are carried out. The test results showed that different manifold angles had little influence on the exhaust temperature uniformity of each cylinder. The diameter of MPC main pipe was reduced to 35% of the original diameter, the standard deviation of exhaust temperature was reduced from 43 ℃ to 30 ℃, and the uniformity of exhaust temperature was significantly optimized.
Keywords:diesel engine; MPC; turbocharging; GT-Power;exhaust temperature uniformity