S109FA燃气-蒸汽联合循环机组RB时汽轮机不卸载的处理及防范措施

Treatment and preventive measures for an unloading steam turbine during the RB of an S109FA gas-steam combined cycle unit

某公司S109FA燃气-蒸汽联合循环机组运行中因防喘放气阀故障造成机组快速减负荷,降负荷过程中出现燃气轮机卸载而汽轮机不卸载的情况,为避免燃气轮机卸载后因主、再热蒸汽温度急跌造成汽轮机金属热应力超限,提出了机组出现异常后的处理原则及防范措施。

In the operation of an S109FA gas-steam combined cycle unit,there was an RB due to the failure of the blow off valve. During the load-reduction process,steam turbine did not unload while the gas turbine unloaded. In order to avoid metal thermal stress overrun of the steam turbine caused by the sudden temperature drop of main and reheat steam after the unloading of gas turbine,treatment principle and preventive measures to address the abnormality of the unit are proposed.