不同宽负荷脱硝系统变工况及瞬态性能的对比研究

The load cycling and transient performance were obtained when different wide-load denitration schemes were adopted, i. e., No. 0 high pressure heater, feed water bypass of economizer and flue gas bypass of economizer. Results show that: at 30%THA-100%THA load, the enhancement of SCR system inlet temperature is the largest using economizer flue-gas bypass on the low-temperature superheater side, reaching 31. 2 K on average when the bypass flow is 50%. The standard coal consumption rates increase when economizer bypass schemes are adopted. By adopting economizer flue-gas bypass on the low-temperature superheater and low-temperature reheater sides, the improvement of SCR system inlet temperature can reach 42. 16 K and 27. 56 K, respectively, when the average standard coal consumption rate is increased by 1 g/(kW · h). The lag time of SCR system inlet temperature is very short and the change rate is high, reaching 34. 65 K/min when economizer flue-gas bypass on low-temperature superheater side is a-dopted. Moreover, the temperature change at the inlet of the SCR system has a lag about 1 min when the No. 0 high pressure heater is put into operation, and the average power change rate reaches 10.22 MW/min.