Analysis And Application Research On Characteristic Flow Area Of Steam Tuirbine In Power Plant

The flow passage of steam turbine is the key part of a unit for energy conversion.Once faults occur in the flow passage, it will have great impact on the security andeconomy of a running turbine.Thus, it is necessary to study on fault analysis and faultdiagnosis of the flow passage of steam turbine. Referring to plenty of literatures bothin China and abroad, this paper has carried out detailed research on flow characteristicof the flow passage of steam turbine.Based on Flugel formula, a new concept of characteristic flow area of steamturbines was presented by derivation and deduction, and the definite analyticalexpression of the characteristic flow area was given in this paper. An illustrativeexample is provided to verify the precision of characteristic flow area,and the appliedapproaches of characteristic flow area in the field of operation analysis，variablecondition calculation，monitoring and diagnosis were pointed out . While creatingaccuracy thermal performance file of flow passage, the characteridtic flow area ofsteam turbine and its rate of deviation related to design condition, internal efficiencyratio and internal power were considered.Take a 310MW set for example, based on thefoundation of accuracy thermal performance file of flow passage, applied analysis wascarried out. Moreover, this paper analyzed the problems that usually encountered whengoing on unit performance analysis,such as enthalpy calculation of exhausted steam ,flow calculation of main steam and extraction steam ,enthalpy calculation of extractionsteam in wet steam section, and a computer programme to calculate enthalpy ofexhaust steam and extraction steam in wet steam section was organized.At last,adopting today’s popular figure melt programmatic software LABVIEW as anexploitation platform,a characteristic flow area application software was carried out.This paper conducted analysis and researches combined with practical situation offlow passage of steam turbine. The application of research results can solve diagnosticerror affected by running condition of regenerative system and“reheat phenomena”when using internal efficiency ratio as a criteria. Meanwhile, the results can alsosupply favorable theory basis for operational monitoring, fault diagnosis and variablecondition calculation of flow passage.