低温压力容器大约束结构接管应力分析

摘要

This paper Takes a exist pressure vessel which has been designed by rule in a ac-complished engineering project for example , analyzed the stress of the Nozzle with Serious constraint , and the internal stress distribution of the structure is obtained. Based on the re-sults of the analysis, the stress state is improved,and some necessary measures must be down to the structure of the pressure vessel by relieving the Serious constraints. Compared with the original structure, the stress of the improved structure is obviously decreased, especially in the connection part between the nozzle and the shell. By doing so, the possibility of the weld cracking due to the large local stress is declined significantly,and the leakage in the con-tainer is avoided. The improved design can be used to provide theoretical support in the de-signing of the pressure vessels with the similar structures, especially for the low temperature pressure vessels and the pressure vessels which have low cycle fatigue operating condition.%以某工程项目中采用常规设计方法设计的低温压力容器为例,对现有结构中存在的大约束结构接管进行应力分析,得到其内部的应力分布情况,基于分析结果,对现有结构进行改进.通过对解除大约束后的结构进行应力分析,并与原结构分析结果进行对比,直观地获得这种大约束结构造成的应力水平增加情况,证明去掉大约束结构后接管与壳体连接处的应力水平得到明显改善,降低了由于局部应力过大而产生的焊缝开裂,导致容器发生渗漏的风险,对含有大约束结构接管设备,尤其是低温压力容器及具有低周疲劳工况的压力容器的设计提供了理论支持.