超临界600MW机组冲转时主蒸汽温度偏高的防治措施

COUNTERMEASURES FOR MAIN STEAM OVERTEMPERATURE OF 600 MW SUPERCRITICAL UNIT DURING TURBINE SPEED-UP

某超临界600MW机组冲转时存在锅炉侧主蒸汽温度高、压力低的问题,与汽轮机要求的冲转参数不匹配。对此,提出了维持锅炉燃油量12～13t/h、冲转时退出给水流量低保护、给水流量降至160～180t/h、机组冲转随机投入高低压加热器、给水温度提高到200℃以上等措施,实施后,可控制主蒸汽温度为400℃,主蒸汽压力为6～8.73MPa,锅炉水冷壁壁温在350℃以内,效果良好。解决了冲转时主蒸汽温度偏高的问题,节约了燃油,具有很好的经济性和安全性。

A 600 MW unit supercritical unit encountered the problem of higher temperature and lower pressure of main steam on boiler side during turbine speed - up, which do not fit in with the required parameters during turbine speed-up. To address this problem, the following measures are proposed. keep the fuel consumption at 12 - 13t/h and stop low feedwater protection during speed - up. Reduce the feedwater flow rate to 160 - 180t/h. Put HP and LP heater at soon as the turbine starts to speed up,with the feedwater temperature up to 200 ℃. After the above measures have been implemented, main steam temperature is controlled at 400 ℃, main steam pressure 6 -8.73Mpa and boiler water wall temperature below 350 ℃. In this way, not only main steam overtemperature problem is solved but also fuel is saved. It has both economy and safety benefits.