双燃料柴油机采用柴油微引燃天然气的RCCI(reactivity controlled compression ignition, RCCI)燃烧方式能够优化排放和经济性能。本文研究微引燃柴油采用3次喷射的方式,即预喷、主喷和尾喷分别控制预喷、主喷和尾喷的喷射始点时刻,通过仿真实验的方法研究其对柴油机缸内压力、温度、放热率和NOx生成率的影响。在预喷、主喷、尾喷喷射始点时刻保持不变、引燃柴油总量不变时,改变预喷、主喷、尾喷引燃的喷油量组合,分析其对柴油机排放和燃烧性能的影响。结果表明主喷的喷油始点时刻对其性能影响最大,主喷喷油始点越早,燃烧越晚,NOx生成率越低;当引燃油量不变前提下预喷的油量越多,燃烧中心前移,NOx排放量显著增大。
The dual fuel diesel engine, which adopts the RCCI (reactivity controlled compression ignition) combustion mode of diesel micro pilot combustion of natural gas, can optimize both the emission and the economic performance. In this study, micro pilot diesel was injected at three times, that is pre-injection, main- injection and tail injection. In this study, the three-injection method is introduced as the variables of following experiments. Controlling the start time of pre-injection, main injection and tail injection respectively, the simulating experiments are designed to observe their effects on the cylinder pressure, temperature, heat release rate and NOx generating rate of diesel engine. When the starting points of pre injection, main injection and tail injection as well as the total amount of pilot diesel remain constant, the quantity of pre injection, main injection and tail injection are changed respectively, the influence on emission and combustion performance of dual fuel diesel engine is analyzed. The results show that the starting point of the main injection has the greatest influence on its performance and the earlier the starting point of the main injection, the later the combustion, the lower the NOx generation rate. When the amount of pilot fuel remains unchanged, the more the amount of pre-injecting fuel is, the combustion center moves forward, and the NOx emission increases significantly.
2022,44(1): 108-113 收稿日期:2021-06-09
DOI:10.3404/j.issn.1672-7649.2022.01.021
分类号:U664.121
基金项目:福建省自然科学基金资助项目(2020J01687)
作者简介:陈丹(1970-),女,副教授,研究方向为船舶动力装置性能仿真及故障诊断
参考文献:
[1] Wartsila 31DF product guide[DB/OL]. [2019-03]. https://cdn.wartsila.com/docs.
[2] WU Y, REITZ RD. Effects of exhaust gas recirculation and boost pressure on reactivity controlled compression ignition engine at high load operating conditions[J]. J. Energy Resour. Technol 2015;137: 032210.
[3] 缪雪龙. RCCI新燃烧技术综述[J]现代车用动力, 2014.1(153)P6−13
[4] MACIEJ M, CEMIL B. Understanding the role of low reactivity fuel stratification in a dual fuel RCCI engine –A simulation study [J]. Applied Energy , 2017 (191): 689−708
[5] HOCKETT A G, HAMPSON G, MARCHESE A J. Natural gas/diesel RCCI CFD simulations using multi-component fuel surrogates[J]. International Journal of Powertrains, 2017, 6(1): 76–108
[6] 苏万华, 赵华, 王建昕. 均质压燃低温燃烧发动机理论与技术[M]. 北京: 科学出版社, 2010.
[7] ZHOU Dezhi, YANG Wenming et al. Efficient combustion modelling in RCCI engine with detailed chemistry [J]. Energy Procedia , 2017 (105), 1582−1587
[8] 邓涛. 运行参数对双燃料船用柴油机燃烧和排放性能的影响[J]. 船舶工程, 2019, 41(12): p8–13, 112
[9] 杨城. 柴油/天然气RCCI发动机燃烧与排放的仿真研究[D]. 厦门: 集美大学, 2018
[10] 杨城, 陈丹, 朱钰. 船用中速柴油机性能的优化研究[J]. 内燃机工程 2018, 39(2), P81−86
[11] WEI Lijiang, GENG Peng. A review on natural gas/diesel dual fuel combustion, emissions and performance[J], Fuel Processing Technology, 2016(142): 264–278.