纳米流冷却液雾化射流缸盖鼻梁区的表面换热分析  

The Effect of Nano-Coolant Atomizing Impingement Cooling on the Surface Heat Transfer in the Cylinder-Head Bridge Zone

作　　者：郑伟[1] 

机构地区：[1]厦门大学嘉庚学院,漳州363105

出　　处：《内燃机工程》2017年第5期148-156,共9页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(51366006);福建省自然科学基金项目(2015J01223);2015年度教育厅福建省高校新世纪优秀人才支持计划;福建省中青年教师教育科研项目(JA15612)~~

摘　　要：提出了采用纳米流冷却液雾化冲击冷却提升缸盖鼻梁区高热密度区换热能力的方案,利用计算机仿真计算、高速摄影及内燃机台架系统研究了纳米流雾化冲击对缸盖高热密度区换热效果及不同冷却方案对柴油机工作性能的影响。研究结果显示,采用雾化冲击方式能实现缸盖高热密度区的良好冷却且温度一致性较好,温度值相差幅度不高于6℃。原因在于纳米流冷却液沸腾换热以核态沸腾为主,且雾化冲击冷却方式可以提升柴油机缸盖的进气质量流量,相比传统冷却方式最大可以提升9.7%的质量流量。在中高转速下NOx排放量和烟度值的最大降幅分别为2.7%和4.0%,在中低转速下HC及CO排放量的最大降幅分别为10.2%和5.3%。In order to further enhance the heat transfer capacity of cylinder head bridge zone of diesel engines, a nano-coolant atomizing impingement cooling was proposed. To this end, the effect of atomizing impingement of nano-coolant on the heat transfer efficiency of cylinder head bridge zone and the influence of different cooling methods on the diesel engine performance were studied by using computer simulation, high-speed photography and integrated bench test system. Results show that the atomizing impingement can achieve efficient cooling of the cylinder head zone and have good temperature uniformity with the m a x i m u m temperature difference of less than 6 °C . This is because the surface heat transfer in the bridge zone is dominated by the nucleate boiling of nano-coolant ？ and the atomizing impingement cooling can increase the cylinder head intake air mass flow rate by 9. 7 % compared with the traditional cooling methods. This allows to have lower NOx and smoke emissions at medium and high speeds with the reduction of H C and CO emissions at low and medium speeds.

关 键 词：柴油机 缸盖 纳米流 雾化冲击 沸腾换热 试验研究 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]