ASPEN thermodynamic consistency check

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Hello everyone: I have been looking at examples of Aspen’s thermodynamic consistency checks recently and have tried to carry out such checks myself. For some binary substances, the checks succeed, while for others they fail; there are also cases where it shows “NOT performed”. The following conditions have been confirmed: 1. The number of data points is greater than 5. 2. There are no pure substances among the data points, and the entire concentration range is covered. 3. The data uses Aspen’s built-in vapor-liquid equilibrium data. However, two issues arose during execution; it’s not clear whether they are related to regression problems or something else. The problems are described as follows: First case: *** DRS CONVERGED IN 2 ITERATIONS, BUT CONSTRAINTS ARE NOT TIGHTLY CONVERGED *** * WARNING WHILE EXECUTING DRS CASE: “DR-2” CONSTRAINTS NOT (TIGHTLY) SATISFIED FOR THIS CASE. Second case: BEGIN CASE DR-1 TIME = 0.00 STARTING POINT TIME: 0.00 *** MEASUREMENT ADJUSTMENT FAILED - BRITT-LUECKE IS LIKELY TO FAIL *** BL-ITER: 1 SSQ: 0.638898E+08 REL CHANGE: 0.00 TIME: 0.02 BL-ITER: 2 SSQ: 0.134691E+08 REL CHANGE: 0.382E-06 TIME: 0.02 FINAL SSQ: 0.397102E+07 *** DRS STOPPED DUE TO 10 LINE SEARCHES FAILED *** * WARNING WHILE EXECUTING DRS CASE: “DR-1” LINE SEARCH FAILURE FOR THIS CASE. I hope experts can help resolve these issues. Thank you very much