船用柴油机三层壁水套排气管衬管故障分析与优化

Failure analysis and optimization of exhaust pipe liner of marine diesel engine with triple wall water jacket

针对某船用柴油机三层壁水套排气管内部衬管开裂的故障,对其进行结构优化,将原有的不锈钢冲压衬管改为铸造衬管,同时通过螺栓将衬管固定在水套排气管上。基于热机耦合方法,采用Abaqus软件对衬管进行温度场和低周疲劳分析,并对优化后的铸造衬管结构进行仿真验证。结果表明:优化后的衬管安装更加方便,且仅有一段衬管存在低风险,最低低周疲劳循环可达5275次;优化方案有效地解决了柴油机三层壁水套排气管衬管开裂的问题,提高了柴油机的可靠性。

In order to solve the inner liner cracking fault of the exhaust pipe with triple wall water jacket on a marine diesel engine,its structure of the inner liner of the exhaust pipe with triple wall water jacket was optimized.The original stainless steel stamping liner was changed into a cast liner which was fixed on the exhaust pipe by bolts.Based on the thermal-mechanical coupling method,the temperature field and low cycle fatigue of the cast liner were analyzed by Abaqus software,and the optimized cast liner structure was verified by experiment.Results show that the optimized structure is more convenient to be installed,only one section of liner has low risk,and the minimum low cycle fatigue life can reach 5275 times.The improved scheme effectively solves the problem of triple wall water jacket exhaust pipe liner cracking and improves the reliability of the diesel engine.