Experimental Investigation on the Stress of Supercritical and Dense Phase Co2 Pipeline System in the Venting Process

Abstract

During the discharge of supercritical and dense-phase CO2 from pipelines, the high-pressure jet undergoes a drastic phase change and rapid depressurization, resulting in a significant temperature drop. This process generates substantial reverse thrust on the pipeline body and its supports. This experiment studied the maximum stress in various pipeline sections during the vertical and horizontal release of supercritical and dense-phase CO2 at pressures ranging from 7.5 MPa to 10.0 MPa and temperatures between 25°C and 40°C. A practical formula for the external thrust generated by the discharge of supercritical and dense-phase CO2 from the pipeline was derived. Our findings indicate that the maximum stress occurs near the first support, primarily due to the excessive strength of a single support. During CO2 release, the pipeline experiences severe vibrations, leading to excessive longitudinal and hoop stresses.

Keywords: supercritical and dense-phase CO2, reverse thrust, pipeline stresses, pipe support, vibration