Nonlinear wave modeling and dynamic analysis of high-purity heat integrated air separation column

•New natural wave velocity and instant wave velocity of HIASC are first derived.•Disturbing wave is analyzed on the basis of natural wave velocity distribution.•Nonlinear wave model of HIASC is established based on instant wave velocity.•Nonlinear dynamic behaviors of HIASC are analyzed based on the new wave model.

A new natural wave velocity of heat integrated air separation column (HIASC) is first derived to describe the concentration traveling tendency of each tray, where the disturbing wave is analyzed on the basis of the natural wave velocity distribution. In order to describe the whole concentration wave of HIASC and to consider the change of the wave profile, a wave profile trial function is further introduced to obtain another useful new wave velocity expression, i.e. instant wave velocity. Then a nonlinear wave model of HIASC is finally established based on above instant wave velocity, and the comparative researches with the mechanistic model built in our previous work are carried out to test the precision of the wave model, whose integral absolute value of error is around 2 × 10−5 and integral square value of error is around 4 × 10−9. At last, nonlinear dynamic behaviors of HIASC are analyzed based on the wave model. The research results show the validity of the proposed nonlinear wave model of HIASC.

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