Energy, Vol.85, 543-555, 2015
Investigating the effect of channel angle of a subsonic MHD (Magneto-Hydro-Dynamic) generator on optimum efficiency of a triple combined cycle
In this research, subsonic flow in a MHD (Magneto-Hydro-Dynamic) generator has been simulated and its influence on efficiency and power generation of a triple combined cycle has been investigated. A 2D variable cross-section Faraday channel with segmented electrodes was utilized as a MHD generator model. MHD flow assumed to be ideal with low magnetic Reynolds number. The proposed triple cycle consists of an open MHD channel as a topping cycle, a gas turbine as a middle generator and a steam turbine as a bottoming cycle. A code including the equations, governing the triple cycle behavior, has been developed to analyze the performance of the combined cycle based on MHD generator. The optimum efficiency of 71.32% was attained for the triple cycle that is obviously greater than the efficiency of a combined cycle without MHD generator which was estimated to be 40.89%. Also the maximum net power output of 42.9 MW was obtained by the triple cycle based on a diverging MHD generator with 5.7 degrees diverging angle. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords:MHD (Magneto-Hydro-Dynamic);Faraday MHD generator;MHD based combined cycle;Efficiency;CFD (computational fluid dynamics) of channels