燃料掺氢对船用天然气发动机燃烧和排放的影响

Effects of Hydrogen Addition in Fuel of Marine LNG Fueled Engines on Combustion and Emissions

为研究船用天然气发动机气体燃料中掺入不同比例氢气对燃烧和排放的影响,运用改装的氢气-天然气-柴油三燃料混烧发动机进行台架实验,测试对比负荷特性下掺氢比为0%,5%,10%,15%四个工况发动机排放物中CO,CO2,NO,NOx,烟温等数据,然后针对掺氢比分别为0%,5%,10%,15%,20%,25%的六个工况,运用CHEMKIN-PRO模拟计算点火延迟时间和层流火焰速度。结果显示,随着氢气比例增加,缸内燃烧点火延迟时间缩短,缸内最高温度升高,层流火焰速度增快,掺氢比对NOx排放影响不明显,相同输出功率下掺氢比高的工况CO排放更低,燃料掺氢工况CO2排放低于纯天然气工况。研究认为,燃料掺氢有助于改善船用LNG动力发动机的燃烧和排放。

In order to study the effects of adding different proportions of hydrogen in fuel of marine LNG fueled engines on combustion and emissions,a bench test of hydrogen-natural gas-diesel mixed-fired engine was conducted,and the hydrogen ratios under the test load characteristics were 0%,5%,10%and 15%.CO,CO2,NO,NOx,and smoke temperature data under four operating conditions were measured.Then for the six working conditions,with hydrogen adding ratios of 0%,5%,10%,15%,20%and 25%,use CHEMKIN-PRO simulation to calculate the ignition delay time and laminar flame speed.The results show that with the increase of the hydrogen ratio,the combustion ignition delay time in the cylinder is shortened,the maximum temperature in the cylinder and the laminar flame speed increase.The hydrogen adding ratio has no obvious effect on NOx emissions.However,at the same output power,the CO emission is lower under the high hydrogen mixing ratio,and the CO2 emission of fuel mixed with hydrogen is lower than that of pure natural gas.It is considered that the hydrogenation of fuel can improve the combustion and emission of marine LNG-powered engines,and has research and application prospects.