Energetic, Exergetic and Exergetic Cost Analysis for a Cogeneration System Integrated by an Internal Combustion Engine, HRSG and an Absorption Refrigeration System

The objective of this work is to do an energetic, exergetic and thermoeconomic analysis of a cogeneration system. This system is composed of an internal combustion engine, a heat recovery steam generator (HRSG), an absorption refrigeration system (ARS) and a cooling tower (CT). With the use of the mass and energy balances, several parameters of efficiency based in the First Law of Thermodynamics were calculated for the cogeneration system. With the use of the exergy balance, the exergetic efficiencies for the engine, HRSG, ARS, CT and the total system were calculated. Also, the irreversibility contribution of each system component was shown. An optimization was done, having as functional objective the maximization of the difference of the operational incomes and expenses. An exergetic cost analysis was made using the Theory of the Cost Exergetic (TCE). The system in study gets to save up to 28,5% of fuel in comparison with the divided production of heat and electric energy. The largest irreversibility that happened in the cycle is due to the engine, which participates in the average with 78% of the total. The analysis with the TCE showed that the product of the ARS is more expensive in comparison with the process heat and electricity.