Off-design operation of an 900 MW-class power plant with utilization of low temperature heat of flue gases

This article presents the off-design operation of a 900 MW-class steam turbine cycle upgraded with utilization of low-temperature waste heat taken from boiler flue gas. The low-temperature heat contributes to increasing the efficiency of power plants without introducing many complex changes to the whole system. The base for investigations was a power unit operating in off-design conditions and supplied with steam from a BB-2400 boiler. Modifications to the model were made using commercially available software and by applying the Stodola equation and the SCC method. Calculations for off-design conditions show that, after making some modifications to the system, both heat and electricity generation could be increased through the addition of a low-temperature heat exchanger.