聚甲氧基二甲醚对柴油机低温燃烧机理影响的基础理论研究

In the current study, fundamental investigation on the effects of Polyoxymethylene Dimethyl Ethers (POMDME) on the low temperature combustion process and mechanism will be conducted. Optical diagnostics, multi-dimensional simulations and test bench experiments will be applied to study the spray breakup, evaporation and mixing characteristics of diesel/POMDME fuel; Reduced multi-component chemical kinetic combustion mechanisms and soot precursor PAH formation mechanisms that are suitable for low temperature combustion simulations for diesel and POMDME fuels will be developed; The effects of POMDME on the combustion characteristics, performance and pollutant emissions, as well as the evolution processes of important intermediate species, free radicals and soot of low temperature combustion diesel engine will be explored; Cooperative control strategies on operating parameters, fuel properties and combustion control under low temperature combustion conditions will be proposed, and optimized control strategy on combustion control, optimization and emission control will be developed. Such study will deepen the understanding on the POMDME reaction mechanism and its influence on the combustion mechanism and emission control strategy of diesel low temperature combustion, and has important guiding value on developing suitable alternative fuels for traditional diesel fuel, reducing the dependency on petro-based fuels, improving the utilization efficiency of coal and development of available technical routines to achieve clean and high efficiency diesel combustion.

本项目将系统开展聚甲氧基二甲醚（POMDME）对柴油机低温燃烧机理影响的基础理论研究。采用光学诊断、数值模拟和台架试验相结合的研究方法，系统研究柴油/POMDME混合燃料的喷雾混合特性，构建适用于低温燃烧多维数值模拟的柴油/POMDME混合燃料燃烧化学反应动力学模型和碳烟前驱物多环芳烃PAH生成动力学机理和碳烟模型；研究POMDME对柴油机低温燃烧的燃烧特性、性能和有害排放，以及主要中间产物、自由基和碳烟的演化历程等的影响；柴油/POMDME混合燃料低温燃烧条件下工况参数、燃料特性与燃烧控制参数的协同控制策略；柴油/POMDME混合燃料低温燃烧控制、优化和有害排放物控制策略。该研究对于深入认识POMDME燃料燃烧化学反应机理和其对柴油机低温燃烧燃烧机理和排放控制策略的影响具有重要的理论意义，对于寻求柴油机新型替代燃料、降低对石油的依赖、探索实现柴油机高效清洁燃烧的技术途径具有重要指导价值。

聚甲氧基二甲醚（PODE或POMDME）是一种新型清洁替代燃料，来源于煤炭或生物质等，能显著改善柴油机燃烧和排放性能，受到国内外的高度重视。本研究综合采用光学诊断、数值模拟和台架试验等方法，研究PODE对柴油机低温燃烧过程和有害排放物形成的影响机理，创新性地提出了适用于柴油/PODE混合燃料压燃、汽油/PODE混合燃料压燃和汽油/PODE RCCI低温燃烧的TRF-PODE-PAH化学动力学反应机理，包含151种物质和654步反应。构建了发动机三维数值模拟平台，揭示了PODE对柴油机低温燃烧油气混合特性、燃烧反应路径、有害排放物形成、关键物种演变过程以及碳烟生成和氧化历程的影响机理。应用PODE燃料结合喷油策略和EGR等协同控制方法，提出了改善柴油机低温燃烧和排放性能的控制策略。该研究对于深入认识PODE燃料燃烧化学反应机理和其对柴油机低温燃烧燃烧机理和排放控制策略的影响具有重要的理论意义，对于寻求柴油机新型替代燃料、降低对石油的依赖、探索实现柴油机高效清洁燃烧的技术途径具有重要指导价值。