Eventos Anais de eventos
CONEM 2022
XI Congresso Nacional de Engenharia Mecânica - CONEM 2022
Experimental study and simulation of Organic Rankine Cycle using R134a
Submission Author:
RICHARDSON LEANDRO NUNES , SP , Brazil
Co-Authors:
RICHARDSON LEANDRO NUNES, Juliana Silva Brasil, Thalles Coimbra Borba Roldão , Luben Cabezas Gómez, Cristiano Tibiriçá
Presenter: Juliana Silva Brasil
doi://10.26678/ABCM.CONEM2022.CON22-0661
Abstract
Consumption from all energy sources in the last 55 years has increased by 275% worldwide, 494% in South and Central America and 1150% in Brazil. 80% of this energy is fossil (oil, natural gas and coal). In Brazil, 80% of the energy consumed is renewable, being 61% hydroelectric, 9% wind, 9% biomass and biogas and 1% centralized solar. The use of fossil fuels worldwide is directly related to carbon dioxide, which is the main cause of greenhouse effect. This is gradually increasing the temperature of the planet by retaining more heat accumulated in the earth from the solar radiation incident on the planet. The decrease in the use of fossil energy sources, the increase in the use of renewable energy sources and increase in energy efficiency, from generation to consumption, contributes to the reduction of carbon dioxide emissions and its undesirable effects. Systems that operate according to the Rankine cycle allow the production of electrical energy from thermal sources. Traditionally, water is used as a working fluid and high temperature energy sources, above 370°C, mainly steam boilers. The Organic Rankine Cycle (ORC) uses organic fluids that have temperatures and evaporation pressures between 60° and 250°C, allowing the use of heat from sources with lower temperatures to generate electricity. In the cycle, the fluid is pressurized by the pump to the evaporator, where it heats at almost constant pressure and turns into saturated or superheated vapor. The vapor expands in the expander (turbine, scroll, etc.) producing shaft work and decreasing enthalpy. Finally, it condenses in the condenser at practically constant pressure, returning to the pump. The main objective of this work is the thermodynamic modeling and the accomplishment of experimental measurements of a system operating according to an organic Rankine cycle (ORC) with R134a. The thermodynamic behavior of the cycle was computationally simulated through the Ideal Rankine Cycle model, calculating the thermodynamic states between each process of the cycle and the resulting performance characteristics. Simulation and experimental results were obtained for operating pressures from 14 to 19 bar, vapor temperatures from 55°C to 77°C and mass flow rates from 30 to 71kg/h. The results show that the experimental workbench is working properly in a wide operating conditions range.
Keywords
Organic Rankine Cycle, renewable energy, Alternative fuel, R134a
