Performance and economic advantages of MHD retrofit

The retrofitting of existing power plants with an open-cycle MHD system has been re-examined in light of recent developments in heat- and seed-recovery technology. Specifically, seed-laden combustion gases are introduced into the conventional furnace under certain select conditions which will assure that the seed particles will be solid when the gas reaches the pendant superheater tube bank. To achieve these selected conditions, as well as meet the objectives of a decoupled gas and steam system, a separate (and new) low-temperature gas path has been proposed. Using this system configuration, substantial increases in efficiency were obtained. Although the analysis was performed for a specific plant (Vermilion Station No. 1 in Oakwood, Illinois) certain aspects of the cycle arrangement are typical of what would be required for other types of coal-fired power plants. As part of this re-examination of retrofit, the economic picture was also reviewed. The cost effectiveness of MHD retrofit was analyzed under three different scenarios. First, the cost of an MHD retrofit was compared against the cost of a new contentional coal-fired plant. Secondly, the cost of an MHD retrofit was compared against the cost of a scrubber retrofit. Thirdly, the economic benefit from MHD retrofit was extrapolated tomore » larger size plants. From these economic studies it was concluded that there is a potential economic benefit from MHD retrofitting.« less