Modelagem e otimização termoeconômica de superestruturas de ciclos kalina para aproveitamento do calor rejeitado em usinas termelétricas com motores de combustão interna

Abstract

In this work, the modeling and optimization is performed using the Engineering Equation Solver (EES) software to harness the heat from two thermal rejects, cooling water and exhaust gas, from internal combustion engines (MCI) of a thermoelectric plant using Kalina cycles, with a Kalina superstructure integrated into the thermoelectric plant which takes into account the consumption of the radiators, the cooling tower and the back pressureeffect. Themodelinginvolvesseveral basic alternatives capable of producing, individually or in association, electric energy and counts with ahighcycle taking advantage of the exhaust gases and another lowcycle taking advantage of the engine cooling water. The optimization performed is parametric and structural, with the objective of maximizing profit, and selecting which cycle produces power withlower cost.Thermodynamic and economic modeling are performed for this work, which considerfourteen decision variables to meet the high and low cycles. The main contribution is to determine the best configuration based on the thermoeconomic optimization,aiming to increase the power generation of the Viana UTE without the need for additional fuel use. The results showed that in the optimum condition it is possible to obtain an increase of about 7.5% of the power generated by the thermoelectric plant.