Modeling for the performance evaluation of 600 MW supercritical unit operating No.0 high pressure heater

Adding the No.0 high pressure heater to raise feed water temperature has been proven to be an effective way to increasing input rate of selective catalytic reduction device (SCR) under low load in coal-fired power plant. However, the method has heavy influence on the operation economy of unit. To quantitatively evaluate the influence of feed water temperature on the operation performance of unit, a simplified one-dimensional nonlinear model for a 600 MW super critical unit with No.0 high pressure heater was presented based on methods of furnace heat balance, differential deviation and thermodynamics, and validated by the field operation parameters. Meanwhile, the impact of feed water temperature on the performance of unit was discussed, and the influence mechanism of it was obtained. The results obtained from incurrent study could provide useful guidance in choosing the optimal process that can help increase efficiency and acquire a reasonable Start-Stop of SCR system in super critical units with No.0 high pressure heater.