The analysis of organic regenerative cycles is necessary to verify the possibilities of increasing the work and efficiency of a thermodynamic cycle according to some control parameters. The results obtained from this ...The analysis of organic regenerative cycles is necessary to verify the possibilities of increasing the work and efficiency of a thermodynamic cycle according to some control parameters. The results obtained from this work can be beneficial in several areas such as solar thermal energy. Simulations of an organic regenerative cycle with up to 4 extractions were carried out in order to analyze the behavior of maximum efficiency and the work generated in the turbine. R134a was used as an organic fluid, used in low temperature cycles. Evaporation temperature data between 60°C and 100°C and superheat temperatures equal to 120°C, 200°C and 300°C were tested for cycle analysis. Thus, it was possible to verify the work behavior and maximum efficiency depending on the number of extractions, superheating temperature and evaporation temperature. The models and simulations were made using the Engineering Equation Solver (EES) software and the results were analyzed in Excel. It was concluded that the maximum efficiency increases with the increase of the evaporation temperature and the number of extractions and decreases with the increase of the superheat temperature. The turbine work grows by increasing the evaporation and superheat temperatures, but decreases with the increase in extractions.展开更多
The optimum efficiency and net work of the regenerative cycle with turbine extractions, using steam as the working fluid, have been simulated and analyzed. The cycle is simulated with until five feed water heaters in ...The optimum efficiency and net work of the regenerative cycle with turbine extractions, using steam as the working fluid, have been simulated and analyzed. The cycle is simulated with until five feed water heaters in a numeric method and can be easily used in solar power plants. The general expression for each component is realized through the balance of energy, collectors, turbine, condenser, pumps and feed water heaters. One analytical method is developed considering constants of the difference of enthalpy through feed water heaters as also between them. The results show that the analytical method is unsatisfactory because the optimum efficiency depends on some parameters such as evaporating temperature and superheating temperature showing in numeric method. The increase of optimum efficiency increases when the number of feed water is increased as well as evaporating and superheating temperature, for the net work presents a maximum value along evaporating temperature, decreasing with number of feed water heaters and increasing when the superheating temperature is increased. The pressure of extraction of turbine is also analyzed, varying about 5% along of evaporation temperature. This analysis is important to motivate the use in solar plants that it is considerate in this paper, just analyzing the cycle.展开更多
文摘The analysis of organic regenerative cycles is necessary to verify the possibilities of increasing the work and efficiency of a thermodynamic cycle according to some control parameters. The results obtained from this work can be beneficial in several areas such as solar thermal energy. Simulations of an organic regenerative cycle with up to 4 extractions were carried out in order to analyze the behavior of maximum efficiency and the work generated in the turbine. R134a was used as an organic fluid, used in low temperature cycles. Evaporation temperature data between 60°C and 100°C and superheat temperatures equal to 120°C, 200°C and 300°C were tested for cycle analysis. Thus, it was possible to verify the work behavior and maximum efficiency depending on the number of extractions, superheating temperature and evaporation temperature. The models and simulations were made using the Engineering Equation Solver (EES) software and the results were analyzed in Excel. It was concluded that the maximum efficiency increases with the increase of the evaporation temperature and the number of extractions and decreases with the increase of the superheat temperature. The turbine work grows by increasing the evaporation and superheat temperatures, but decreases with the increase in extractions.
文摘The optimum efficiency and net work of the regenerative cycle with turbine extractions, using steam as the working fluid, have been simulated and analyzed. The cycle is simulated with until five feed water heaters in a numeric method and can be easily used in solar power plants. The general expression for each component is realized through the balance of energy, collectors, turbine, condenser, pumps and feed water heaters. One analytical method is developed considering constants of the difference of enthalpy through feed water heaters as also between them. The results show that the analytical method is unsatisfactory because the optimum efficiency depends on some parameters such as evaporating temperature and superheating temperature showing in numeric method. The increase of optimum efficiency increases when the number of feed water is increased as well as evaporating and superheating temperature, for the net work presents a maximum value along evaporating temperature, decreasing with number of feed water heaters and increasing when the superheating temperature is increased. The pressure of extraction of turbine is also analyzed, varying about 5% along of evaporation temperature. This analysis is important to motivate the use in solar plants that it is considerate in this paper, just analyzing the cycle.
