Using new packages for modelling, equation oriented simulation and optimization of a cogeneration plant

The development and testing of an equation-oriented (EO) mathematical model for the optimization of heat and power systems using a new state-of-the-ar t sequential quadratic programming (SQP) method called filterSQP has been r eported in an earlier paper. The model has been extended to include combine d cycle cogeneration plants (CCCPs), the economic optimization of which inv olves adding equipment investment, cost functions and operating cost models to the stream and unit operation models of the earlier paper. These system s are of substantial industrial interest and are substantially larger than those in Rodriguez-Toral et al., Computers and Chemical Engineering, August 2000. Their size and complexity required the use of a new flexible modelli ng system (FMS) recently created within our research group. FMS can be used to setup large systems of equations, create networks to be modelled and gi ve starting guesses easily for problems of any size. Also, FMS is able to i nteract with solvers for EO simulation and optimization, which have been de veloped here and elsewhere. A number of EO simulation and optimization exam ples, from simple unit operations to a whole real cogeneration plant involv ing a commercial gas turbine with 1275 variables and equations, are used to demonstrate the applicability of the CCCP model and the modelling package. (C) 2000 Elsevier Science Ltd. All rights reserved.