Influences of Load Command Signals on the Operation Characteristics of Coal-Fired Power Plants During Loading up Processes

In recent years an increasing number of coal-fired power plants are forced to take part in load cycling to balance the electricity demands and supplies in China. Therefore, the investigation of energy consumption characteristics of power plants during transient processes is necessary and valuable. In this paper, the loading up processes of a power plant with several formats of load commands, such as linear, parabolic, sine and exponential functions were simulated, and the energy consumption characteristics of the power plant were presented. Furthermore, the operation characteristics including flexibility, safety and generation cost were compared. Results show that: when the unit increases load with the same average cycling loading rate, the max difference of standard coal consumption rates is 1.03 g/(kW h), which decreases with the increase of average cycling rate. The excellent signal formats have the following features: the instantaneous cycling rates are small in the ending of a transient process while they have high values in the beginning and mid-stage of the process. (CSPE)