柴油引燃天然气火焰温度场和碳烟浓度场分析  

An analysis of the flame temperature field and soot concentration field of diesel ignition injection natural gas

作　　者：王定文 董全[1] 倪佐 樊旭 夏天峰 WANG Dingwen;DONG Quan;NI Zuo;FAN Xu;XIA Tianfeng(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》2024年第9期1735-1743,共9页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51879056).

摘　　要：针对柴油引燃高压直喷天然气火焰温度场和碳烟浓度场尚不明确的问题,在定容燃烧弹平台上,采用高压直喷天然气共轴喷射器,利用高速彩色相机结合双色法研究了不同油/气喷射压力和油/气喷射间隔对高压直喷天然气燃烧后的火焰温度和碳烟KL值分布特性。研究结果表明:高压天然气被引燃后的火焰平均温度和碳烟平均KL值均随着油/气喷射压力的升高而降低,因此为降低碳烟KL值应提高油/气喷射压力。当油/气喷射间隔为0.8 ms时,高压天然气射流火焰平均温度最高,最高达到2318 K;当喷射间隔为0.4 ms时,火焰的平均温度最低,最低为2148 K;相同时刻下,油/气喷射间隔0.8 ms的碳烟平均KL值相较于0.4 ms的工况最多提高了112.8%,相较于喷射间隔1.2 ms的工况最多提高了49.02%;试验结果表明:为降低高压直喷天然气燃烧时的碳烟生成水平,应将喷射间隔设定在柴油喷射结束之前。本文为HPDI天然气发动机的燃料喷射策略和降低碳烟生成的相关研究提供基础参考。In response to the problem that the flame temperature field and carbon soot concentration field of diesel-ignited high-pressure direct-injection natural gas are still unclear.On a constant-volume combustion bomb platform,a high-pressure direct injection(HPDI)natural gas coaxial injector was used to study the distribution characteris-tics of flame temperature and soot KL value after HPDI natural gas combustion under different diesel/gas injection pressures and diesel/gas injection intervals using a high-speed color camera and the dual-color method.This study provides a basic reference for the fuel injection strategy of HPDI natural gas engines and for related research on re-ducing soot formation.The results show that the flame average temperature and soot average KL value decrease with the increase in the diesel/gas injection pressure after high-pressure natural gas is ignited.Thus,the diesel/gas in-jection pressure should be increased to reduce the soot KL value.When the diesel/gas injection interval is 0.8 ms,the average temperature of the high-pressure natural gas jet flame is the highest at up to 2318 K.When the injec-tion interval is 0.4 ms,the average temperature of the flame is the lowest at 2148 K at most.At the same moment,the average KL value of soot at a 0.8 ms diesel/air injection interval is increased by 112.8%at most compared with that at 0.4 ms and increased by 49.02%at most compared with that at a 1.2 ms injection interval.The experimen-tal results show that,to reduce the soot formation level during high-pressure directly injected natural gas combus-tion,the injection interval should be set before the end of diesel injection.

关 键 词：高压直喷 双色法 定容弹 天然气 碳烟 火焰温度 喷射压力 喷射间隔 

分 类 号：TK437[动力工程及工程热物理—动力机械及工程]