The study presented in this paper investigated the performance of a proposed system constructed from Brayton, two parallel inverse Brayton and Rankine cycles. It has been carried out by varying the Brayton cycle pressure ratio for different values of expansion pressures of the two inverse Brayton cycles using variable inlet pressures, above atmospheric. The results revealed that the best theoretical performance could be achieved when the system was simulated with a high value of expansion pressure of the second inverse Brayton cycle. Also, it was shown that, as a result of altering the expansion pressure of the second inverse Brayton cycle, the range of the upper cycle pressure ratio increased and the system attained a high thermal efficiency (54 per cent).

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Abstract. High temperature fuel cells such as the solid oxide fuel cell (SOFC) and the molten carbonate fuel cell (MCFC) are considered extremely suitable for electrical power plant application. The molten carbonate fuel cell (MCFC) performances is evaluated using validated model for the internally reformed (IR) fuel cell. This model is integrated in Aspen Plus TM . Therefore, several MCFC/Gas Turbine systems are introduced and investigated. One of this a new cycle is called a heat recovery (HR) cycle. In the HR cycle, a regenerator is used to preheat water by outlet air compressor. So the waste heat of the outlet air compressor and the exhaust gases of turbine are recovered and used to produce steam. This steam is injected in the gas turbine, resulting in a high specific power and a high thermal efficiency. The cycles are simulated in order to evaluate and compare their performances. Moreover, the effects of an important parameters such as the ambient air temperature on the cycle performance are evaluated. The simulation results show that the HR cycle has high efficiency.