Influence of low temperature and flow properties in dynamic behaviour of cryogenic pipelines

The dynamic behaviour of cryogenic fluid pipelines under varying conditions and environments plays a vital role in the design of cryogenic systems. The natural frequency of the cryogenic fluid pipeline varies due to the changes in physical properties of materials with respect to change in the operating temperatures. The dynamical characteristics of the system are determined from its natural frequencies and damping ratios. Induced thermal stress in stainless steel pipelines is caused by pipeline contraction during low temperature service. It is controlled by expansion loops in the pipeline excite at regular intervals along the length. This however significantly alters the natural frequency of the system. This paper describes the influence of a low temperature environment on the dynamic behaviour of a cryogenic fluid pipe line. Thermo-structural FEM analysis has been carried out to find the effect of low temperature in the cryogenic fluid line and the results are compared with experimental data.