Technical and economic analysis of heat exchange with big temperature difference based on heat recovery from power plant exhaust steam

This article compares several different heat supply systems based on heat recovery from exhaust steam. Thermal and electrical parameters are compared among different heat-supply systems of 300MW Units such as traditional extraction condensing turbine system, small temperature difference heat-supply system and large temperature difference heat-supply system. When the large temperature difference heat-supply system is operating with 400t/h of extraction flow, the consumption rates of coal equivalent for power supply and heating are respectively 318.225g/(kW·h) and 27.899kg/GJ in the heat-supply period. The capacity of power supply and heating of large temperature difference system show a rise of 17.7MW and 317.1MW compared with that of traditional extraction condensing turbine system.