method for operating a waste heat steam generator

摘要

The method involves connecting a bypass line (4) on a flow medium side to a set of economizer heating surfaces (10, 14) of an economizer in a parallel manner. A parameter e.g. saturation temperature of an evaporator (16), that is characteristic of thermal energy fed to a waste heat steam generator (1) is utilized for controlling or regulating a flow rate of the bypass line. A power of a gas turbine is utilized as the parameter that is characteristic of thermal energy, where the gas turbine is connected upstream to the waste heat steam generator. An independent claim is also included for a waste heat steam generator with an evaporator and an economizer including a set of economizer heating surfaces.