Exergy analysis and exergoeconomic assessment of trigeneration system: a case study

Abstract

An energetic and exergetic analysis based on the first and second thermodynamic laws, and an exergoeconomic assessment by the SPECO method was applied to a trigeneration system. Two LiBr/H2O absorption chillers and a diesel combustion engine integrate. The system was proposed to meet the energy demands of a resort in Piaui in northeast Brazil. A numerical program for the trigeneration system simulation was developed. The effective electrical power of the generator and thermal load provided by the chillers were 192 kW and 260.45 kW, respectively. For water heating, the capacity found was 127.68 kW at two temperature levels, 40°C and 60°C. The overall efficiency system was evaluated by the energy utilisation factor (EUF). The EUF for the trigeneration system was 81.6%. The engine and the double effect absorption chiller high-pressure steam generator presented the largest sources of destroyed energy and the most considerable portion of the total installation cost.