Minimization of natural gas and water consumption in the operation of utility plants

摘要

The main objective of this paper is to report reductions in water, natural gas consumption and operating cost obtained by choosing optimally the operating conditions of a real utility plant. There are continuos and discrete optimisation variables, therefore a Mixed Integer Non Linear Programming problem is solved with the code GAMS. The main continuous operating variables to be selected are temperature and pressure of the high, medium and low-pressure steam headers, de-aerator tank pressure and flow rates such us letdowns and vents. Binary variables are introduced for the selection of boilers, pumps and drivers. A rigorous simulation of the steam and power generation plant was developed interfacing a subroutine for water property prediction. The numerical results quantify the improvements that can be expected in the utility sector by selecting the continuos and discrete operating variables.