某船用柴油机排气管路流-固耦合计算与保温效果研究

The Fluid-Solid Coupled Calculation and Analysis of the Heat Preservation Effect of the Exhaust Piping System on a Marine Diesel Engine

对某船用柴油机排气管路的流动与传热过程开展流固耦合仿真分析。结果表明:受排气管路结构影响,管内流动方向和流速发生变化,局部区域产生明显的回流现象;排气管路外表面温度分布差异较大,平均温度高达534℃。为达到柴油机安全设计要求,在排气管路外壁敷设保温材料。分析结果表明:气凝胶纳米材料的保温效果优于硅酸铝纤维材料,在相同的运行条件和使用要求下,气凝胶纳米材料的敷设厚度更薄。

The fluid-solid coupled simulation analysis was carried out to study the the flow and heat-transfer process of the exhaust piping system of a marine diesel engine.The results showed that the flow direction and velocity changed due to the influence of piping structure and significant backflow occurred in part of the areas.There were obvious temperature differences among external surfaces of the exhaust piping system and the average temperature was up to 534℃.To meet with safety requirements of the diesel engine design,heat preservation material was used to cover the out-wall the piping system.The analysis results show that the heat preservation effect of aerogel nanometer material is superior to aluminum silicate fiber,which resulted in the installation thickness of Aerogel nanometer material being thinner under the same operation conditions and requirements.