Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Exergy analysis of a coupled unit to produce electrical energy and cold water
Submission Author:
Ronelly Souza , PB
Co-Authors:
Ronelly Souza, João Medeiros, Carlos Antonio Cabral Santos
Presenter: Ronelly Souza
doi://10.26678/ABCM.COBEM2017.COB17-1179
Abstract
This work presents an exergetic analysis of an Organic Rankine Cycle (ORC), used for recovery energy from low temperatures heat sources, connected to a Single-Effect Absorption Refrigeration System (ARS). Both are based on heat sources with reduced energetic availability cost such as biomass, geothermal, waste heat and solar energy. The ARS data were consulted in a catalog of commercial Absorption Chillers. The connection between the systems is essentially made through thermal exchanges involving the ORC condenser and a cold water storage tank located between the ARS and the ORC. Using the same heat source, the combination of both systems aims to produce the cooling effect and mechanical power, besides increasing the overall efficiency of the system. Classic thermodynamics models have been developed based on the determination of some input parameters such as the heat available at the thermal source, the pressure ratio in the ORC system and the cooling capacity of the ARS. The ORC system studied works with R134a as working fluid, whereas the ARS works with the lithium bromide-water pair. The simulation results showed that the connection between both systems, using the same heat source, increases the mechanical power of the ORC from 0.65 kW to 7.05 kW for an ARS cooling capacity varying from 5 TR to 50 TR. The energy efficiency remained the same (about 27%) for the same cooling capacity range, whereas the exergy efficiency increased from 49.6% to 51.2%.
Keywords
Organic Rankine Cycle, Absorption Refrigeration System, Coupled Unit, Exergetic Analysis
