Reproducible issues of non-convergence and inconsistent results were encountered in the Aspen LDPE process

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This post was last edited by Eason_w74rq on 2020-1-9 at 11:55. Dear colleagues, I am facing difficulties in the current verification process. I have entered all the reaction conditions, mass transfer data, and reaction kinetics specified in the literature into Aspen, but the calculation does not converge; moreover, the values of PDI.MWN and MWW at the exit points differ from those given in the literature. I was wondering if any of you could help me identify the issue. Thank you very much. Reference: 2014, Wang Yuliang, Study on Mixing Characteristics in LDPE Batch Reactors. ** ERROR: Liquid root did not converge in EOS model POSL03; T = 10.00, PSPEC = 0.1600E+09, PCALC = -0.2090E+09. ** ERROR: Liquid root did not converge in EOS model POSL03; T = 10.00, PSPEC = 0.1600E+09, PCALC = -0.2090E+09. *** SEVERE ERROR: Single-phase temperature calculations failed after 6 iterations. Final temperature is 10.0000; final enthalpy is -4.7614D+07, while the specified enthalpy is -5.3975D+07. Errors occurred in the flash calculations for tear stream S13. ** ERROR: Liquid root did not converge in EOS model POSL03; T = 23.31, PSPEC = 0.1600E+09, PCALC = 0.3251E+08. ** ERROR: Liquid root did not converge in EOS model POSL03; T = 23.31, PSPEC = 0.1600E+09, PCALC = 0.3251E+08. ** ERROR: Liquid root did not converge in EOS model POSL03; T = 10.00, PSPEC = 0.1600E+09, PCALC = -0.8106E+08. ** ERROR: Liquid root did not converge in EOS model POSL03; T = 10.00, PSPEC = 0.1600E+09, PCALC = -0.8106E+08. *** SEVERE ERROR: Single-phase temperature calculations failed after 6 iterations. Final temperature is 10.0000; final enthalpy is 2.9172D+07, while the specified enthalpy is -1.3938D+07. Errors occurred in the flash calculations for tear stream S13. * WARNING: Convergence block $OLVER06 did not converge after 30 iterations. ** ERROR: Convergence block $OLVER06 did not converge normally during the final pass