柴油引燃天然气发动机诱导火焰射流燃烧模式分析

沈照杰¹，赵华²，王彦岩¹，纪兆圻¹，马琮淦¹，康玉霞³

1.哈尔滨工业大学（威海） 汽车工程学院，山东 威海  264209；

2.布鲁奈尔大学先进动力与燃油研究中心，英国 伦敦  UB83PH；3.广西玉柴机器股份有限公司，广西 玉林  537005

摘要：为提高天然气燃烧速率，突破天然气发动机在低负荷工况下碳氢排放高、燃烧效率低，以及高负荷工况下爆震倾向显著等技术瓶颈，系统研究柴油引燃天然气发动机的引燃优化与火焰传播增强技术进展。厘清缸内预混天然气燃烧加速机制的关键科学问题，重点解析引燃柴油喷射调控、缸内火焰传播强化和诱导火焰射流三种燃烧组织模式。分析表明：提高引燃效率、加快火焰传播速度、维持火焰传播稳定及缩短火焰传播距离是解决天然气燃烧速率低的主要技术思路；诱导火焰射流燃烧方式结合柴油多点引燃和预燃室火焰射流，通过节流环设计使引燃火焰向余隙区高速射流，可以缩小缸内各区域燃烧始点、持续期及火焰传播距离差异，加快天然气火焰传播速度，是实现缸内天然气快速燃烧的潜在技术路径；节流环结构还有很大优化空间，应开展相关基础研究以推进该技术的发展和应用。

关键词：柴油-天然气双燃料发动机；燃烧优化；余隙燃烧；诱导火焰射流燃烧

Analysis of induced flame jet combustion mode of diesel ignited diesel-natural gas dual fuel engine

SHEN Zhaojie¹, ZHAO Hua², WANG Yanyan¹, JI Zhaoqi¹, MA Conggan¹, KANG Yuxia³

1. School of Automotive Engineering, Harbin Institute of Technology, Weihai 264209, China；

2. Centre for Advanced Powertrain & Fuels, Brunel University, London UB83PH, UK;

3. Guangxi Yuchai Machinery Co., Ltd., Yulin 537005, China

Abstract: To improve the combustion process of natural gas, this paper systematically investigates the research progress on ignition optimization and flame propagation enhancement technologies for diesel and natural gas dual fuel engines. By clarifying the core scientific issues of the in-cylinder premixed natural gas combustion acceleration mechanism, the characteristics of three combustion organization modes, regulation of diesel injection, enhancement of in-cylinder flame propagation enhancement, and new combustion mode of induced flame jet are emphatically analyzed. The analysis results indicate that the main technical paths to accelerate natural gas combustion include improving ignition efficiency, enhancing flame propagation speed, maintaining stable flame propagation, and shortening flame propagation distance. The induced flame jet combustion mode represents a potential way to speed up combustion of natural gas by integrating multi-point auto-ignition of diesel with flame jets generated through a throttle ring. In this mode, the combustion flame is injected into the clearance region at high speed, the differences of the start of ignition, combustion duration, and flame propagation distance among different regions in the cylinder will be effectively reduced. To further optimize natural gas combustion performance, the throttle ring structure can undergo additional refinement. Meanwhile, clarifying the mechanism of induced flame jet combustion is essential to promote the technology′s development and practical application.

Keywords: diesel-natural gas dual fuel engine; combustion optimization; clearance combustion; induced flame jet combustion