【作者】 王贵新；

【导师】 柳贡民；

【作者基本信息】 哈尔滨工程大学 ， 轮机工程， 2012， 博士

【摘要】 能源危机与环境污染问题的日益突出，对柴油机的经济性、动力性和排放提出了更高的要求，从而导致现代柴油机向高功率密度、低油耗、低排放的方向发展。影响柴油机性能指标的因素很多，其中以燃油系统、进气系统和燃烧系统最为显著。因此，柴油机油-气-室的优化匹配技术越来越受到人们的重视。目前对于可控进气涡流柴油机的油-气-室的分析研究多集中在单一系统的研究，缺少对油-气-室相互匹配及其内在联系的全面分析。特别是对于可控进气涡流柴油机的燃烧系统，以前的研究多集中在一维的仿真计算分析，没有系统全面的进行三维的燃烧分析。本文针对以上研究现状，以可控进气涡流柴油机为研究对象，在对其燃油系统、进气系统和燃烧系统进行计算分析的基础上，提出各个系统的优化设计方案，以实现柴油机油-气-室的优化匹配，并利用进气系统和燃油系统的专项试验来验证计算分析的准确性。本文主要的研究工作包括以下几个方面：1．应用HYDSIM燃油系统分析软件，研究柴油机泵-管-嘴燃油喷射系统的基本特性和性能指标随结构参数的变化规律，对可控进气涡流柴油机的燃油喷射系统进行优化设计。即以改善喷油的雾化特性为设计目标，对柴油机喷油泵柱塞直径、高压油管内径、喷油器喷孔长径比等关键结构参数进行优化匹配设计，研究影响柴油机喷油特性和雾化指标的内在规律，为燃油系统优化设计和后续的缸内燃烧分析及喷油雾化试验提供理论依据和计算数据。2．应用FIRE进气系统流场分析软件，对可控涡流柴油机进气流场进行计算分析。重点研究气阀升程、挡板结构和气道结构对柴油机进气系统流场的影响规律，分析不同气阀升程和不同气道挡板开度下进气系统的涡流比、流量系数、流速和压力等关键性能指标，研究柴油机进气涡流的形成机理。在对可控涡流柴油机进气系统详尽分析的基础上，优化进气道挡板和气道结构，以改善柴油机的进气涡流和进气流量，实现柴油机进气系统的优化设计。3．应用FIRE燃烧系统分析软件，对可控涡流柴油机进行缸内三维燃烧计算分析和优化设计。重点分析涡流比对燃油雾化、油气混合和缸内燃烧的影响规律，分析涡流比对柴油机动力性指标和排放指标的影响规律；对比分析不同喷油规律对柴油机缸内燃烧性能指标的影响规律，以及喷油规律对柴油机排放指标、燃油雾化和油气混合的影响规律，通过对比分析优化出最佳的喷油规律；研究柴油机进气系统挡板和气道结构对缸内燃烧过程的影响规律，优化出最佳的挡板结构和气道结构。进而完成柴油机油-气-室的优化匹配分析。4．根据可控涡流柴油机进气系统的实际结构，搭建其进气系统稳流试验台，完成试验设计。试验中分别针对不同气阀升程和不同挡板开度对柴油机进气系统的涡流比和流量系数等重要性能指标进行试验测试，完成实测数据与流场计算结果的对比分析，验证流场计算分析的准确性。5．建立双进气道可控进气涡流柴油机喷油雾化试验台，采用可视化技术和高速摄影技术对柴油机的喷油雾化过程进行动态试验测试。重点分析进气涡流对喷雾的贯穿距离、喷雾锥角和油气混合的影响规律，研究在不同的涡流比下进气涡流对柴油机油雾宏观状态的影响规律；利用喷油雾化实测数据来验证缸内油气混合计算结果的正确性，同时为柴油机燃油雾化的内在机理研究奠定试验基础。更多还原

【Abstract】 As the energy crisis and the environmental problems have become increasinglyprominent, the higher requirements of the economy, dynamic property and emission of dieselengine have been brought forward. So that the higher power density, lower fuel consumptionsand lower emissions would be the development orientation of modern diesel engine. There aremany factors impacting the engine performance indicators, and among them the fuel system,the air intake system and the combustion system of diesel engine are the most important.Therefore, the optimized matching technology of the diesel fuel-air-chamber is paid more andmore attention.At present, most of the fuel-air-chamber researches on controllable intake swirl diesel areless focus on comprehensively analyzing the matching and the inner connection between thefuel, air and chamber, but on single system. Especially on the combustion system ofcontrollable intake swirl diesel engine,1D simulation analysis had been carried out mostly inprevious studies, and fully systematic3D combustion analysis was less been done.According to present research situation, this paper took one controllable intake swirldiesel as the study object, proposed the optimization design schemes which were based on thecalculation analysis for the fuel injection system, the air intake system and the combustionsystem, in order to realize the diesel fuel-air-chamber optimized matching. Also the specialtests of the air intake system and the fuel injection system had been done to verify theaccuracy of the calculation analysis. During the process of system analysis and optimizationdesign, to reveal the inner mechanism of each system of the controllable intake swirl diesel,and using the modern analysis technology to optimize and to match the dieselfuel-air-chamber, the system optimization overall the diesel engine was achieved. The mainresearch work includes the following aspects:Firstly, by adopting the specialty software HYDSIM, the fundamental characteristics ofthe pump-tube-nozzle type diesel fuel injection system and the rules of performanceindicators changing with structure parameters have been studied in order to makeoptimization design of the controllable intake swirl diesel engine fuel injection system. Toimprove the injection spray characteristics, the key structure parameters such as the fuelinjection pump plunger diameter, the high-pressure tube diameter and the length-diameterratio of the nozzle holes have been optimized. Meanwhile, by studying the inner influence mechanism of the fuel injection characteristics and spray quality, the results could provide thetheoretical basis and calculated data for the optimization design of the fuel injection systemand the follow-up studies on combustion analysis and injection spray field test in cylinder.Secondly, by using the CFD software FIRE, the calculation analysis on the intake flowfield of the controllable intake swirl diesel engine have been done. The detailed studies are onthe influence rules of the diesel intake flow field impacted by the valve lift, the bafflestructure and the intake airway structure. Analyzing some key performance indicators such asthe swirl ratio, the flow coefficient, the air velocity and pressure of the diesel air intakesystem in operation conditions with different valve lifts and different intake baffle angles is tostudy the formation mechanism of diesel intake swirl. Based on the detailed analysis on theair intake system of the controllable intake swirl diesel, the structure optimizations on thebaffle and the intake port have been done to improve the intake swirl and inlet flow, and toachieve the optimization design of the diesel air intake system.Thirdly, by adopting the combustion analysis software FIRE, the3D burning calculationanalysis and optimization design in cylinder of the controllable intake swirl diesel have beentaken. The influence rules analysis of the swirl ratio impacting the fuel spray situation, thefuel-air mixture and in-cylinder combustion situations have been paid great attention.Comparatively analyzing the different injection laws effecting the in-cylinder combustionperformance indicators, the detailed studies on the influence rules that the injection lawsaffected the emission indicators, spray atomization and fuel-air mixture of the diesel engineare conducted, and obtained the final optimal fuel injection law. By studying the influencerules of the baffle structure and intake port structure of the diesel air intake system effectingthe in-cylinder combustion process, the optimization structure parameters of the baffle andintake port could be gained. Then the optimal matching design of the diesel fuel-air-chamberhave been finished.According to the air intake system physical structures of the controllable intake swirldiesel engine, the steady flow test rig of the air intake system should be built to finish theexperiment design. The key performance indicators of the air intake system such as the swirlratios and the flow coefficients are measured under the conditions of different valve lifts anddifferent baffle angles in the test. The comparative analysis between the measured data andthe calculated data verifies the accuracy of the flow field calculation.A spray test rig of the controllable intake swirl diesel engine with double intake portshave been set up to dynamically measure the injection spray process with the visualizationtechnology and the high speed photography. The detailed study on the influence rules of the intake swirl impacting the penetration, spray angle and fuel-air mixture situations are done toanalyze the effects of different intake swirl ratios in spray macro states. The accuracy of thein-cylinder fuel-air mixture calculation results is validated by the field test data of the spraytest, and the spray test lays the basis of the inner mechanism research on spray atomization ofthe diesel engine.更多还原