Boiler heat transfer quantity calculation method and device

The present invention addresses a problem in which the prediction accuracy for the heat transfer quantities of heat exchangers disposed in various locations of a pulverized coal fired boiler is reduced. Provided is a boiler heat transfer quantity calculation device for determining, in a boiler that carries out pulverized coal firing, the quantity of heat transferred by combustion gas to heat exchangers inside the boiler, said boiler heat transfer quantity calculation device being characterized by being provided with a first function for determining a combustion gas distribution inside the boiler, a second function for carrying out heat transfer calculation using the combustion gas distribution determined by the first function and determining the heat transfer quantity for each heat exchanger location in the boiler, a third function for calculating the particle size of the coal ash in the heat exchanger piping created by pulverized coal firing, and a fourth function for using the coal ash particle size determined by the third function to determine the wavelength dependency of the coal ash emittance in the heat exchanger piping, and being characterized by the second function being such that the wavelength dependency of coal ash emittance given by the fourth function is used to determine the heat transfer quantity of each heat exchanger location in the boiler.