Influence of Plant Steam System on Thermal Economy of Thermal Power Plant and Energy Strategy

When the unit is under normal operating, the steam source of plant-steam is from the fourth steam extraction of turbine. But at the low load operating condition, during the process that the steam source of plant steam switches to reheat cold section from the fourth steam extraction, steam power capability in the turbine is further reduced. In this paper, in order to improve the economy when the turbine is operating under the low load, reheat cold section steam is used as high-pressure steam to extract the fourth steam by the steam technology, which turns the low-pressure steam into the medium-pressure steam for recycling. This paper, taking 300MW unit as an example, discusses the influence on the thermal economy of unit after putting the steam ejector into the plant steam system of thermal power plant.