小管径垂直管水下排气完全携带点试验及分析  

Experiment and Analysis of Zero Liquid Penetration Point of Vertical Underwater Exhaust Pipes with Small Diameter

作　　者：陆鹏[1] 宋大为 朱奎 马有福[2] 邵杰 LU Peng;SONG Dawei;ZHU Kui;MA Youfu;SHAO Jie(Shanghai Marine Diesel Engine Research Institute,Shanghai 200090,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]中国船舶重工集团公司第七一一研究所,上海200090 [2]上海理工大学上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《船舶工程》2020年第11期71-74,113,共5页Ship Engineering

摘　　要：为防止海水由排气管倒灌入船舶柴油机造成事故,需弄清水下排气管内水倒流发生的条件。当前对大管径垂直管防止水倒灌临界条件(即完全携带点)已有较为统一的认识,而对小管径垂直管的认识还不清晰。为此,在25 mm^100 mm管径范围内对垂直管的完全携带点进行试验,探究小管径垂直管的完全携带点预报方法。试验结果表明,在小管径范围内,垂直管完全携带点对应的临界表观气速随管径的增大而升高,气相Wallis数随管径的增大而减小,说明Wallis数过度关联了管径对临界表观气速的影响。基于气相Kutateladze数和无量纲气相黏性,对小管径垂直管提出了新的完全携带点预报模型和相应的试验关联式。In order to prevent the diesel engine from a damage caused by the seawater pouring back into the diesel from the exhaust pipe,it is necessary to clarify the occurrence condition of water backflow in exhaust pipes.There have been an unified understanding on the zero liquid penetration(ZLP)point of vertical pipes with large diameter,whereas the understanding on that of vertical pipes in small diameter is not yet clear.For it,the ZLP points of vertical exhaust pipes are tested in the diameter range of 25 mm^100 mm to study the prediction method of ZLP points of vertical exhaust pipes with small diameter.The results show that,in small diameter range,the critical superficial gas velocity corresponded to the ZLP point increases with the increase of diameters,while the gas phase Wallis number tends to decrease with the increase of diameters.It indicates that,for the vertical pipe in small diameter,Wallis number presents an excessively correlation to the effect of diameter change on the critical superficial gas velocity.A new prediction model that is a combination of Kutateladze number and dimensionless viscosity,as well as a corresponding correlation,are proposed for the ZLP point of the vertical pipe with small diameter.

关 键 词：水下排气 垂直管 完全携带点 预报模型 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]