深度调峰超临界直流炉机组快速降负荷工况过热汽温控制

Superheated steam temperature control of supercritical once through boiler under the condition of deep peak regulation and fast load reduction

为提高深度调峰机组快速降负荷工况下过热汽温控制品质,针对超临界直流炉过热汽温系统各扰动因素定性分析,机组快速降负荷动作过程中,给煤量突降后给水控制环节存在惯性与迟延,导致机组快速降负荷过程水煤比严重偏高,是过热汽温快速降低的主要因素,提出超临界直流炉快速降负荷工况下过热汽温控制策略,通过对给煤量控制增加惯性环节,降低给煤量下降速率,减小水煤比偏高对过热汽温的影响。仿真结果表明:改进后的过热蒸汽温度下降幅度减小30%,中间点温度下降幅度减小34%,降低机组快速降负荷过程中因过热蒸汽温度低跳闸的风险,提高机组安全稳定运行可靠性。

In order to improve the quality of superheated steam temperature control under the condition of fast load reduction of deep peak load regulation unit,qualitative analysis is made on the disturbance factors of superheated steam temperature system of supercritical once through boiler.In the process of fast load reduction of the unit,there is inertia and delay in the feed water control link after the sudden decrease of coal feed quantity,which leads to the high water coal ratio in the process of fast load reduction of the unit,which is the main factor for the rapid decrease of superheated steam temperature.The control strategy of superheated steam temperature under the condition of fast load reduction of supercritical once through boiler is put forward.By adding inertia link to the control of coal feeding quantity,the rate of decrease of coal feeding quantity is reduced,and the influence of high water coal ratio on superheated steam temperature is reduced.The simulation results show that the temperature drop range of the improved superheated steam is reduced by 30%,and the temperature drop range of the intermediate point is reduced by 34%,which reduces the risk of tripping due to the low temperature of the superheated steam in the process of rapid load reduction,and improves the safe and stable operation reliability of the unit.