喷管结构及位置对天然气发动机燃烧特性的影响  

The influence of structure and position of natural gas nozzle on combustion characteristics of a natural gas engine

作　　者：杨立平 桑卫辉 宋恩哲[1] 王佳琦 刘振廷 YANG Liping;SANG Weihui;SONG Enzhe;WANG Jiaqi;LIU Zhenting(College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001, China)

机构地区：[1]哈尔滨工程大学动力与能源工程学院,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2020年第11期1663-1668,1726,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51306041).

摘　　要：针对多点喷射天然气发动机喷气与进气协同问题,本文考虑燃气射流与进气道内空气的交互作用以及进气及时性,利用三维数值仿真分析方法,研究喷气射流方向和喷嘴位置对燃气与空气混合及燃烧过程的影响。结果表明:随着天然气射流与空气来流方向夹角的增加,天然气与空气碰撞和混合几率增加,在进气道内和缸内天然气与空气混合更加充分,但在进气道内的燃气残留增加,与0°喷管相比,90°喷管进入气缸内的燃料量减少4.7%,采用45°与60°喷管时,缸压峰值与0°喷管相当,但放热率峰值降低、NO排放减少。随着喷嘴喷气出口位置逐渐接近进气门,进气道内燃气残留减少,与原90°喷管相比,放热率和缸压峰值均增大,峰值相位提前。As a response to the synergetic problem of gas fuel injection and intake in a multi-point natural gas engine,the influence of the gas jet direction and nozzle position on the mixing and combustion process of the gas fuel and air mixture is studied using a three-dimensional numerical simulation method.Here,the interaction between the gas jet and air in the intake port as well as the timeliness of intake are considered.Results reveal that increased angle between the direction of gas jet and air flow increases collision and mixing probabilities of the gas fuel and air.Consequently,this yields a more homogeneous mixture in the intake port and cylinder.However,a significant increase of the gas residue in the intake port is observed.Similar peak pressures are observed among gas nozzles with 0°,45°,and 60°holes,while a 4.7%fuel reduction into the cylinder is observed using the gas nozzle with 90°holes compared with that from gas nozzles with 0°holes.However,peak heat release rates and NO emissions decrease.As the position of the nozzle outlet gradually approaches the inlet valve,gas residue in the intake port decreases.Compared with the original nozzle with 90°holes both the heat release rate and the peak cylinder pressure increase and the peak phase advances.

关 键 词：天然气发动机 多点喷射 喷管 喷管位置 气体射流方向 混合 燃烧 模拟 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]