Design And Stress Analysis Of High Temperature And High Pressure Compressed Air Pipe In A Key Laboratory

Stress analysis of pipelines is a cross-disciplinary subject spanning materials,metallurgy,material mechanics and other disciplines,for high temperature and high pressure pipelines,the dynamic force of stress analysis research comes from the development needs of national aerospace,nuclear power,petrochemical,military and other industries.most of the projects in this research direction are national key large-scale projects,such as " Russian gas supply to the south",domestic nuclear power engineering,military,aerospace and other fields,and civil building thermal rarely meet the engineering content of relevant parameters.In order to facilitate the design,installation,manufacture,use,acceptance and maintenance of pressure pipeline engineering,finite element method is used to analyze the stress of pipeline under specific operating conditions.A set of high-temperature and high-pressure experimental equipment is constructed in a national key laboratory.the equipment is composed of several equipments,which are connected by pipelines.The medium transported in the pipeline is compressed air,the medium design temperature is 500 ℃～800 ℃,and the maximum design pressure of the pipeline is 40.0 MPa.China’s current pipeline stress calculation using the design code for industrial metal pipeline design code GB 50316-2008 regulation of China’s pressure pipeline design code range is pressure(?)42 m pa,and for the influence of high temperature on the pipeline,the industrial metal pipeline design code GB 50316-2008 provisions of the explanation is only that the use of materials need to use metal materials at temperature,and the choice of materials is not described in detail.Under the high temperature working conditions,the calculation results calculated by the national standard calculation method should be relatively conservative with reference to the United States standard.According to asmi standard,finite element method is used to analyze the stress of pipeline and piping system.In this paper,according to the requirement of engineering practice,the metal material of working steel pipe is selected by numerical simulation method and metallurgical knowledge,and the reliability of pipe making standard and pipe fitting standard is checkced.According to the results of numerical simulation and analysis,it is determined that the main location of stress concentration is elbow of main pipe,tee joint between main pipe and branch pipe and flange joint between branch pipe and equipment.Installing compensator on the main pipe can reduce the main pipe for branch pipe tangential stress,by increasing the wall thickness of the main pipe and elbow,can improve the main pipe stress,but will increase the main pipe for branch pipe tangential stress,using large turning radius elbow can be low elbow stress concentration.The thrust of the branch pipe on the main pipe and the equipment interface flange can be reduced by adding u-shaped bends on the branch pipe and installing compensators on the branch pipe.After the above measures are adopted,the peak stress in the pipe system is reduced to the stress range that the pipe and the pipe fitting can bear,and the pipe can run under the peak stress condition.