Thermal-hydraulic optimization of a steam generator by entropy generation minimization and genetic algorithm method

Abstract

Abstract From the review of literature conducted in recent years, it has become clear that, despite extensive studies to obtain optimal parameters for a variety of thermodynamic systems and industrial equipment, there is still no attempt in this context on the steam generators. Hence, in this paper, we used the entropy generation equations in accordance the second law of thermodynamics, also the Drift-flux method for two-phase flow (introduced by Zuber-Findlay) and the genetic algorithm to optimize a vertical steam generator. The main goal of vertical steam generator optimization is to obtain the optimal parameters as well as to increase the steam generator efficiency and consequently to increase the efficiency of the PWRs. So the effects of all the parameters influencing on a vertical steam generator were initially separate and then simultaneously examined on entropy generation number and the exact optimal parameters for the least entropy generation number using the genetic algorithm are calculated in the MATLAB toolbox. In order to determine the two-phase flow characteristics, a thermal equilibrium mixture model with an algebraic relation between the velocities (or a slip ratio) of the two phases is used. In this study we reduced the entropy generation number value from 0.061 to 0.055 for design parameters, which represents about 10% improvement in entropy generation number. Also, the effectiveness for design parameters has increased from 0.71 up to 0.82.