The heat transfer modelling method based on actual status of the evaporative heating surface for supercritical once-through boiler has been given.On the basis of operation characters concerning the heating surface

the structure of said heating surface and its parameters under polluted status have been determined

the absorbed heat of said heating surface being predicted by adopting the obtained parameters and the heat transfer calculation model of said evaporative heating surface suitable for prediction of enthalpy value at the intermediate point being further given.This model can clearly describe quantitative relationship between the enthalpy value at intermediate point and every affecting factor.Through test of varying the coal sort

the proportioning ratio of water and coal

the load

and the coefficient of excess air of the once-through boiler for supercritical 600 MW unit

it is shown that the said model can accurately predict the enthalpy value at intermediate point;in the event of variation in operation condition of the boiler

the said model can be used to correct the thermodynamic adjusting parameters

guiding the adjustment of steam temperature.