Patent ID: 7430868

Claim:
A method of operating a thermal power plant in which a rotary unit is driven by burning gaseous fuel inside a combustion chamber, with hot gases being formed, the rotary energy of which rotary unit is converted into another form of energy, and describes a load set point (L) of the thermal power plant, the load set point (L) being set by regulating the quantity of gaseous fuel fed to the combustion process, wherein the thermal power plant is operated at a load set point (L), provided the gaseous fuel is fed to the combustion process through a gas line at a gas pressure p gas , with p gas >p action limit ( L ), where p action limit (L) represents a pressure value which depends on a system internal pressure p system requirement (L) set in the region of the combustion chamber by the load set point (L) of the thermal power plant, with p action limit ( L )> p system requirement ( L ), wherein, starting from an initial load set point L 0 , during a pressure loss in the gas line, as a result of which the gas pressure p gas drops to the pressure value p action limit (L 0 ), standard deloading is carried out by reducing the quantity of gaseous fuel fed to the combustion process, and wherein, depending on a pressure ratio between p gas and p action limit (L) forming during reduction of the load, on the basis of a decision criterion, one of the following steps is performed: i) the standard deloading is ended and the thermal power plant is changed to its initial load set point, or ii) complete emergency load shedding is carried out, during which the fuel reduction is carried out more rapidly than during the standard deloading, or iii) the fuel supply is changed over to another type of fuel.