600MW机组五抽膨胀节破裂故障原因及经济性分析

Economic and Failure Cause Analysis of Expansion Joints Rupture in the Fifth Extraction for a 600MW Unit

某电厂超临界600 MW机组运行中五段抽汽压力降为0,造成5号低压加热器解列,机组主蒸汽量大幅增加。通过对运行数据分析及停机后检查,分析了五抽膨胀节破裂的原因及后期运行注意的事项,利用等效焓降法探讨了该故障对机组经济性造成的影响,为同类型机组提供借鉴。

In the operation of a supercritical 600 MW unit of a power plant,the extraction pressure of the unit in the fifth stage drops to 0 MPa,resulting in the disassembly of No.5 low-pressure heater and a significant increase in the main steam volume of the unit.Based on an analysis of the operation data and the inspection after the shutdown,the causes of the rupture of the expansion joints in the fifth extraction and the cautions in the later operation are analyzed.The influence of the failure on the economical efficiency of the unit is also analyzed by using the equivalent enthalpy drop method,so as to provide reference for the same type of units.