Simulation Method for Branched Pipeline Network Coupling Analysis of Physical Properties and Phase Characteristics of Carbon Dioxide

Due to the impact of CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>phase changes on the transportation capacity of CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>pipelines, the thermodynamic calculation equation of CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>pipelines needs to be more closely coupled with the phase property equation for calculation; In CCUS technology, CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> transportation has expanded from pipelines to pipe networks, so it is necessary to construct a CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> pipe network simulation method. To accurately describe the changes in phase characteristics of impurity containing CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> systems, a CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> phase characteristic analysis model is established based on the PR equation to establish a phase equilibrium model. A calculation example of the physical properties and phase characteristics of a multi-component impurity containing CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> system is constructed to compare the predictive performance of the physical property model with PVTsim and REFPROP commercial software. The absolute average relative error is within 8%. Combining physical property prediction models, based on one-dimensional pipe flow characteristic equations and graph theory knowledge, a CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>branched pipe network simulation method is developed.