Numerical Calculation Of 2200MWt MHD-steam Combined Cycle System With Tail Gasification
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This paper discusses the conception of the gasified MHD-steam combined cycle system and sets up a research scheme on the combined cycle system. In this system one part of the high temperature tail gas exiting the MHD channel is utilized to gasify the coal, then the clean syngas is produced in the gasifier. Another part of the tail gas goes into a radiation furnace. Based on this thermal chemical regeneration technique the chemical energy of the syngas is more than that of the coal, and the syngas, as a clean fuel, is combusted in the MHD combustor. In this way, the difficulties brought by ash residue can be overcome. In the gasifier, the sulphur is eliminated by inserting limestone, so the recovered seed is potassium carbonate and the cycle system does not need a seed regeneration unit. The physical models are built and the code is developed. In this paper we have calculated the thermodynamic properties of the system. The parameters of a 2200MWt MHD-steam combined cycle system with tail gasification are determined and the efficiency of this combined cycle system is computed, which is found to be higher than a traditional MHD-steam combined cycle system. 1 Introduction Megnetohydrodynamic (MHD) power generation belongs to one of the direct energy conversion technologies. It utilizes the high-temperature (around 2400K) plasma incising magnetic force line to induce electromotive force for the generation of electric power . The temperature of tail gas from the MHD generator is fairly high, around 2200K. At present the efficiency of the conventional coal-fired thermal generating power plant does not exceed 40% .