Patent ID: 9482427
Filing Date: 2016-11-01
CPC Classification: F22B

Claim Text:
1. A method for operating a once-through steam generator including an evaporator heating surface, comprising: supplying a device for setting the supply water mass flow with a target value for the supply water mass flow; calculating the target value using a ratio of a current heat flow transferred in the evaporator heating surface from a hot gas to a flow medium to a predetermined target enthalpy increase of the flow medium in the evaporator heating surface with respect to a desired live steam state wherein the predetermined target enthalpy increase takes into consideration an actual enthalpy at an evaporator heating surface inlet which is determined using a temperature and a pressure, respectively measured using a temperature sensor and a pressure sensor at the evaporator heating surface inlet; determining the heat flow transferred from the hot gas to the flow medium by taking into account a specific temperature characteristic for the current temperature of the hot gas at the evaporator heating surface inlet and a specific mass flow characteristic for a current mass flow of the hot gas, and wherein the ratio is created using a division element including as a numerator the current heat flow transferred in the evaporator heating surface from the hot gas to the flow medium and as a denominator the predetermined target enthalpy increase of the flow medium in the evaporator heating surface with respect to the desired live steam state.