2023年（第45卷）第8期汽车工程AutomotiveEngineering2023（Vol.45）No.8柴油机喷雾碰壁引燃进气预热特性研究*张翼霄，马骁，卢鑫辉，王志，诸葛伟林，帅石金（清华大学车辆与运载学院，北京100084）［摘要］针对低温环境下重型柴油机的冷起动，提出了喷雾撞击热壁面引燃、回流稳焰的进气预热方案。基于自主设计搭建的预热实验装置，研究了不同风速、喷油落点、喷油策略下的温升和燃烧特性，并开展了CFD数值模拟。实验结果表明：着火和温升对喷油落点呈较强的敏感性，加热板存在最佳位置，风速10m/s下的平均温升速率达到4.24℃/s。为了兼顾温升速率、燃烧效率和维护成本，高风速下须采取喷射周期为20~25ms、喷射脉宽为1~3ms的喷油策略。高速液滴撞击加热板表面后发生回弹和破碎，属于Leidenfrost破碎模式。模拟结果显示：扰流板形成了局部风速低于5m/s的回流区，促进了蒸发和油气混合，有利于着火和火焰稳定；针对喷射频率合理匹配喷射量，本质上是调控燃烧持续期与喷射周期相适应，使燃油充分利用，提高温升和放热速率。关键词：柴油机；进气预热；喷雾碰壁引燃；回流稳焰；数值模拟AnInvestigationonIntakePreheatingCharacteristicsBasedonSprayWallImpingingIgnitionforDieselEngineZhangYixiao，MaXiao，LuXinhui，WangZhi，ZhugeWeilin&ShuaiShijinSchoolofVehicleandMobility，TsinghuaUniversity，Beijing100084［Abstract］Forthecoldstartofheavy-dutydieselengineinlowtemperatureenvironment，anintakepre‐heatingschemeusingsprayignitionbyhotwallimpingingcombinedwithflamestabilizationbyrecirculationispro‐posed.Basedontheself-designedandbuiltpreheatingexperimentapparatus，thetemperaturerisingandcombus‐tioncharacteristicsunderdifferentinflowspeed，fuelspraytargetingandinjectionstrategyarestudied，andCFDnumericalsimulationsareconducted.Theexperimentalresultsshowthatignitionandtemperaturerisearestronglysensitivetospraytargeting，andthereisanoptimalpositionofheatingplate，withthemeantemperaturerisingratereaching4.24℃/sattheinflowspeedof10m/s.Tobalancethetemperaturerisingrate，combustionefficiencyandmaintenancecost，theinjectionstrategywithaninjectionperiodof20~25msandinjectionpulsewidthof1~3msshouldbeadoptedathighinflowspeed.Thefastdropletsreboundandbreakupafterim...
