Thermodynamic analysis of a trigeneration system consisting of a micro gas turbine and a double effect absorption chiller

Combining heating and power systems represent an option to improve the efficiency of energy usage and to reduce thermal pollution toward environment. Microturbines generate electrical power and usable residual heat which can be partially used to activate a thermally driven chiller. The purpose of this paper is to analyze theoretically the thermodynamic performance of a trigeneration system formed by a microturbine and a double-effect water/LiBr absorption chiller. The heat data supplied to the generator of the double effect air conditioning system was acquired from experimental data of a 28 kWE microturbine, obtained at CREVER facilities. A thermodynamic simulator was developed at Centro de Investigación en Energía in the Universidad Nacional Autónoma de México by using a MATLAB programming language. Mass and energy balances of the main components of the cooling system were obtained with water–lithium bromide solution as working fluid. The trigeneration system was evaluated at different operating conditions: ambient temperatures, generation temperatures and microturbine fuel mass flow rate. The results demonstrated that this system represents an attractive technological alternative to use the energy from the microturbine exhaust gases for electric power generation, cooling and heating produced simultaneously.