液氨/二甲醚双燃料高压直喷燃烧特性模拟研究  

Numerical Study on High-Pressure Direct Injection Combustion Characteristics of Ammonia/Dimethyl Ether Dual Fuel

作　　者：陆嘉钰 张程程[1] 何志霞[1] 王谦[1] 戴礼明[1] LU Jiayu;ZHANG Chengcheng;HE Zhixia;WANG Qian;DAI Liming(School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学能源与动力工程学院,镇江212013

出　　处：《内燃机工程》2024年第4期16-28,共13页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金青年项目(52206149)。

摘　　要：基于CONVERGE软件分别对液氨和二甲醚(dimethyl ether, DME)液态燃料高压喷雾过程进行了数值仿真及验证,随后对液氨/DME双燃料高压直喷射流燃烧过程进行数值模拟,探究了两种燃料喷口位置、喷射策略及氨能量占比(ammonia energy ratio, AER)等因素对着火和燃烧特性的影响。结果表明:合理的燃料喷口位置距离可以有效促进氨燃料燃烧,但距离过近会导致DME喷雾受到氨射流喷雾强烈的降温影响,发生失火;与液氨–DME喷射次序相比,DME–液氨策略在高液氨能量占比条件下更能促进液氨充分燃烧;燃烧过程中一氧化氮(NO)集中生成于高温区域而二氧化氮(NO_(2))集中生成于中低温区域;在DME–液氨策略下将喷射间隔时间从0.5 ms增加到1.0 ms时,NO和NO_(2)的生成量减少;液氨能量占比从80%降低到50%时反而会导致NO和NO_(2)生成量增加。Using CONVERGE software,the high-pressure spray process of liquid NH3 and dimethyl ether(DME)liquid fuel were numerically simulated and verified against experimental data from literature,and then the high-pressure direct injection combustion process of liquid NH3/DME dual fuel was numerically investigated.The effects of the nozzle positions,injection strategies,and ammonia energy ratios and other factors on the ignition and combustion characteristics were explored.The results show that reasonable distance of fuel nozzles can effectively promote the combustion of ammonia.But if the distance is too close,DME spray will be strongly affected by the temperature drop of ammonia evaporation,resulting in misfire.Compared with the injection sequence of liquid NH3–DME,the strategy of injecting DME before liquid NH3 can promote the combustion efficiency of NH3 with high NH3 energy ratios.During the combustion process,nitric oxide(NO)and nitrogen dioxide(NO2)are formed in the high temperature region and the medium low temperature region,respectively.When the injection interval between DME and NH3 is increased from 0.5 ms to 1.0 ms,the NO and NO2 formation is reduced.And when the proportion of ammonia energy is reduced from 80%to 50%,the production of NO and NO2 would increase.

关 键 词：氨 二甲醚 燃烧 高压直喷 引燃 NO_(x) 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]