Research And Application On Fault Diagnosis About Flow Path And Condenser Of Thermo-eletric Plant

A fault diagnosis program is developed for the flow path part and condenser part of one petrochemical plant’s inner thermo-eletric plant.In the flow path part, a pressure-flow constant which is specially used for thermo-eletric steam turbine is proposed. The pressure-flow constant is derived step by step and verified with historical data. The constant’s law of change in different faults is pointed out and a formula of the pressure-flow constant and thickness of scaling or abrasion is constructed. Using pressure-flow constant, a formula for diagnosing governing stage is derived. Common fault symptoms is analysed, the condition of using pressure ratio and that of equivalent through the flow area are pointed out, as well as the fact that expansion angle method and internal efficiency method have the same essence. The differences between thermo-eletric steam turbine diagnosis and condensing steam turbine diagnosis in flow path are analysed, and a simple and feasible method which makes every stage group’s diagnosis relatively independent is proposed.In condenser diagnosis part, a diagnosis method for condensers with main recycled water pipe is proposed. Condenser is divided into A and B two parts when diagnosed, a new method for calculating should-reach pressure value of half-to-half condenser is proposed and a corresponding rule table is done. Condenser is diagnosed with fuzzy neural network method, and membership functions are constructed.