ABSTRACT 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.
Cite this paper
Da Cunha, A. , Fraidenraich, N. and Silva, L. (2017) Optimum Efficiency Analysis of Regenerative Cycle with Feed Water Heaters. Journal of Power and Energy Engineering, 5, 45-55. doi: 10.4236/jpee.2017.58004.
 Baumann, K. (1930) Some Consideration Affecting the Future Development of the Steam Cycle. Proceedings of the Institution of Mechanical Engineers, 2, 1305.
 Bejan, A. (1988) Advanced Engineering Thermodynamics. John Wiley & Sons, United States of America.
 Haywood, R.W. (1949) A Generalized Analysis of the Regenerative Steam Cycle for Finite Number of heaters. Proceedings of the Institution of Mechanical Engineers, 161, 157-162. https://doi.org/10.1243/PIME_PROC_1949_161_016_02
 Yinga, Y. and Hub, E.J. (1999) Thermodynamic Advantages of Using Solar Energy in the Regenerative Rankine Power Plant. Applied Thermal Engineering, 19, 1173-1180. https://doi.org/10.1016/S1359-4311(98)00114-8
 Weir, C.D. (1960) Optimization of Heater Enthalpy Rise in Feed-Heating Trains. Proceedings of the Institution of Mechanical Engineers, 174, 769-783.
 Fraidenraich, N., Oliveira, C., Vieira da Cunha, Andre F., Gordon, J.M. and Vilela, O.C. (2013) Analytical Modeling of Direct Steam Generation Solar Power Plants. Solar Energy, 98, 511-522. https://doi.org/10.1016/j.solener.2013.09.037