| A dynamic simulation system for aldehyde unit is developed to simulate normaland abnormal conditions with a super real time speed. The system has beentested in Chemical Plant of Yangzi Petrochemical Corporation and achievedsatisfactory result.A heat exchanger model is presented in detail for effective dynamic simulation.An Average Temperature Approach, which is more suitable for dynamiccalculation is brought forward on the basis of mathematical proof. Thisapproach is not only more steady than the logarithmatic average temperatureapproach but also more accurate and effective by logically supposing that theoutlet temperature and the average temperature run to their steady state valuewith equal proportion.Because the one-step ethylene oxidation reactor is complicated andinteracting and the amount of catalyzer is too little compared to the entirereactant, reaction competition is introduced in the calculation for the reactor. Itmakes the reactor model more accordant for the real time simulation.In flash calculation, a constant volume flash model is adopted. It uses "Inside-Out" approach to determine phase equilibrium parameters, which not onlyguarantees the accuracy and stability, but also improves the speed ofcalculation.For the high mechanism and dynamic characteristics of this software it can notonly be used for the training but also can be applied for the technicalreconstruction. |
