超临界600MW机组不能带满负荷的原因分析

贵港电厂2号机组（超临界600MW）在调试过程中．出现机组无法带满负荷的现象。为查找原因．从数字式电液（DEH）调节系统的控制逻辑、汽轮机调门的流量特性和阀门活动过程等方面进行了分析．并通过阀门在线活动试验．最终确定了机组故障原因是左侧主蒸汽门堵塞或开度很少致使其通流量很小。解体检查发现左侧主蒸汽门阀蝶螺纹衬套脱开，无法带动主阀。重新装配主蒸汽门后．机组试运行正常。

Analysis of a Supercritical 600 MW Unit s Failure to Carry Full Load

Supercritical 600 MW Unit 2 of Guigang Power Plant failed to carry full load during its commissioning test.Consequently,an analysis was made from such aspects as the control logic of the digital electro-hydraulic(DEH) control system,the flow characteristics of the turbine governor valve and the valving process.On-line valve test results showed that the fault was caused by the little flow through the left-side main steam valve with a block or very small opening.Through strip inspection,it was found that the butterfly-valve screw-thread bush of the left-side main steam valve was off and the main valve could not be driven.Satisfactory results were obtained after reassembling the main steam valve.