Achieving Clean Non-Premixed Combustion through Hydrogen Addition

压缩点火发动机和使用非预混火焰的工业燃烧器的进步主要是由于先进的后处理技术。加氢或使用氢作为预混火花点燃（SI）发动机的清洁燃料是相当好的理解和发展。对于压缩点燃（CI，柴油）发动机和工业燃烧器中的非预混燃烧，情况并非如此。本次研究的目的是通过对燃烧过程进行改造，防止污染物的形成，因此不需要后处理，或者至少可以放宽后处理的要求。这项研究将证明，当氢加入到液体燃料流中，形成两相混合物时，可以实现显著的烟尘减少。添加氢有可能通过改变导致烟灰形成和生长的化学途径来减少烟灰，从而有效地降低颗粒物质水平，使燃烧过程更完整。向液体燃料流中添加氢气将使氢气在一定的时间和地点确保其在烟灰形成过程中起到抑制剂的作用，并作为更完全燃烧的催化剂。液体燃料/氢混合物的形成方法及其喷射工艺是本课题需要解决的主要问题。利用光学可及的混合室对两相的喷射和燃烧进行了研究。在这个阶段，将使用高速数码相机的各种光学可视化技术。两相混合燃料的最终实施将在三缸压缩点火发动机上进行。发动机的加油系统将被重建，以实现两相混合物的形成和喷射。发动机的气缸安装了压电传感器，以获得压力测量值，随后分析热量释放和燃烧相位参数。随着国内外对新氢经济的兴趣和投资不断增长，从拟议的氢补充研究中毕业的学生将很容易就业，需求量很大。

Progress in compression ignition engines and industrial burners that use non-premixed flames has been made mostly due to advanced aftertreatment technologies. The hydrogen addition or use of hydrogen as a clean fuel for premixed spark-ignited (SI) engines is fairly well understood and developed. The same is not true for non-premixed combustion in compression-ignited (CI, diesel) engines and industrial burners. The proposed research aims to prevent pollutants formation through combustion process modification, so there will be no need for the aftertreatment or at least the requirements for the aftertreatment can be relaxed. This research will demonstrate that significant soot reduction can be achieved when hydrogen is added to the liquid fuel stream, to form a two-phase mixture. The hydrogen addition has the potential to reduce soot by modifying the chemical paths that lead to soot formation and growth, in effect lowering the particulate matter levels and making combustion process more complete. The addition of hydrogen to the liquid fuel stream will place hydrogen in the locations and at the time that ensure its acting as an inhibitor in the soot formation process and as a catalyst for more complete combustion. The methodology of forming liquid fuel/hydrogen mixture and its injection process are the major issues to be resolved in the proposed research. Using an optically accessible mixing chamber the injection and combustion of two-phase will be investigated. Various optical visualization techniques with a high speed digital camera will be used at this stage. The final implementation of the two-phase mixture fuelling will be done on a three-cylinder compression ignition engine. The fuelling system of the engine will be rebuilt to enable the two-phase mixture formation and injection. The engine's cylinders are fitted with piezoelectric transducers to obtain pressure measurements that are subsequently analyzed for heat release and combustion phasing parameters. With nationally and internationally growing interest and investments in new hydrogen economy, students who will graduate from the proposed research on hydrogen supplementation will be easily employable and in high demand.