ON-LINE CALCULATION METHOD OF EXHAUST STEAM' S ENTHALPY

The on-line calculation of exhaust steam's enthalpy for steam turbines is an important link in thermodynamic performance test and on-line supervision of thermal power units.At present,the calculation method of exhaust steam's enthalpy has certain limitations in varying degree,hence,it is necessary to analyse and compare the algorithms of exhaust steam's enthalpy.The commonly used calculation methods for exhaust steam's enthalpy are as follows:energy balancing method,curve's extrapolation method,equivalent enthalpy drop method ,Fulugel formula's method,and relative internal efficiency method.By using these said methods,the exhaust steam's enthalpy of a N220-12.7 type steam turbine has been calculated respectively as concrete examples.Through analysis and comparison of the calculation results,the individual condition of application and measures of improvement for these said calculation methods have been obtained .