Method for operating a waste heat steam generator

摘要

A method for operating a waste heat steam generator including an evaporator, an economizer having a number of economizer heating surfaces, and a bypass line connected on the flow medium side in parallel with a number of economizer heating surfaces is provided. The method makes possible higher operational safety and reliability in the control of the waste heat steam generator. For this purpose, a parameter that is characteristic of the thermal energy fed to the waste heat steam generator is used to control or regulate the flow rate of the by-pass line.

主权项

1. A method for operating a waste heat steam generator, comprising:
providing the waste heat steam generator with an evaporator, an economizer with a first plurality of economizer heating surfaces, and a bypass line connected in parallel with a second plurality of economizer heating surfaces on a flow medium side; and using a variable that is characteristic of a thermal energy supplied to the waste heat steam generator to control or regulate a flow rate through the bypass line, and wherein a power output of a gas turbine connected upstream of the waste heat steam generator on a flue gas side is used as the characteristic variable for the thermal energy supplied to the waste heat steam generator, wherein a temperature device and pressure device are provided at the inlet to the evaporator in order to respectively measure the temperature and pressure at the inlet to the evaporator, wherein the temperature device and pressure device at the evaporator inlet are used for controlling or regulating the flow rate through the bypass line, wherein a saturation temperature in the evaporator, determined from the pressure measurement at the evaporator inlet, is used for controlling or regulating the flow rate through the bypass line, and wherein as a result of the controlling or regulating the flow rate through the bypass line the temperature at the inlet to the evaporator includes a deviation from the saturation temperature.