Integrated power plant and method of operating such an integrated power plant

A method of operating an integrated power plant, comprising the steps of:

• providing an integrated power plant, the integrated power plant including a gas-turbine set with a compressor, a combustion chamber and a gas turbine, a heat-recovery boiler arranged downstream of the gas turbine, and a water/steam circuit with a steam generator fired separately from said gas turbine with respect to a combustion air used having a flue-gas NOx-reduction unit arranged downstream of the steam generator, the heat-recovery boiler being incorporated in the water/steam circuit, wherein a branch line is provided at the heat-recovery boiler, by means of which branch line a predetermined portion of the exhaust gases coming from the gas-turbine set and flowing through the heat-recovery boiler is branched off and is added upstream of the flue-gas NOx-reduction unit to the flue gases flowing through the steam generator, a predetermined portion of the exhaust gases coming from the gas-turbine set and flowing through the heat-recovery boiler is branched off and is added upstream of the flue-gas NOx-reduction unit to the flue gases coming from the steam generator, wherein the flue gas is delivered from the steam generator to a stack by means of an induced-draft fan arranged downstream of the steam generator, and in that the induced-draft fan is operated in such a way that the exhaust-gas-side pressures in the heat-recovery boiler do not change.

A method of operating an integrated power plant, comprising the steps of:

• providing an integrated power plant, the integrated power plant including a gas-turbine set with a compressor, a combustion chamber and a gas turbine, a heat-recovery boiler arranged downstream of the gas turbine, and a water/steam circuit with a steam generator fired separately from said gas turbine with respect to a combustion air used having a flue-gas NOx-reduction unit arranged downstream of the steam generator, the heat-recovery boiler being incorporated in the water/steam circuit, wherein a branch line is provided at the heat-recovery boiler, by means of which branch line a predetermined portion of the exhaust gases coming from the gas-turbine set and flowing through the heat-recovery boiler is branched off and is added upstream of the flue-gas NOx-reduction unit to the flue gases flowing through the steam generator, a predetermined portion of the exhaust gases coming from the gas-turbine set and flowing through the heat-recovery boiler is branched off and is added upstream of the flue-gas NOx-reduction unit to the flue gases coming from the steam generator, wherein the flue gas is delivered from the steam generator to a stack by means of an induced-draft fan arranged downstream of the steam generator, and in that the induced-draft fan is operated in such a way that the exhaust-gas-side pressures in the heat-recovery boiler are reduced and the output of the gas turbine is increased as a result.

An integrated power plant, comprising:

• a gas turbine arrangement including a compressor, a combustion chamber, and gas turbine, hot exhaust gases of said gas turbine flowing through a heat-recovery boiler arranged downstream of said gas turbine to exit the power plant after having passed said heat recovery boiler;
• a water/steam circuit with a steam generator which is fired separately by burning coal with fresh combustion air not being part of said hot exhaust gases of said gas turbine, said steam generator having a flue-gas NOx-reduction unit arranged downstream of the steam generator, the heat-recovery boiler being incorporated in the water/steam circuit;
• a branch line for branching off a predetermined portion of the exhaust gases coming from the gas turbine arrangement and flowing through the heat-recovery boiler, the exhaust gases being added upstream of the flue-gas NOx-reduction unit to the flue gases flowing through the steam generator,
• wherein the heat-recovery boiler contains a heating-surface system for generating and/or superheating steam for the water/steam circuit, and in that the branch line branches off from the heat-recovery boiler downstream of the heating-surface system in the exhaust-gas-side direction of flow.

An integrated power plant, comprising:

• a gas turbine arrangement including a compressor, a combustion chamber, and gas turbine, hot exhaust gases of said gas turbine flowing through a heat-recovery boiler arranged downstream of said gas turbine to exit the power plant after having passed said heat recovery boiler;
• a water/steam circuit with a steam generator which is fired separately by burning coal with fresh combustion air not being part of said hot exhaust gases of said gas turbine, said steam generator having a flue-gas NOx-reduction unit arranged downstream of the steam generator, the heat-recovery boiler being incorporated in the water/steam circuit;
• a branch line for branching off a predetermined portion of the exhaust gases coming from the gas turbine arrangement and flowing through the heat-recovery boiler, the exhaust gases being added upstream of the flue-gas NOx-reduction unit to the flue gases flowing through the steam generator,
• wherein the heat-recovery boiler contains a heating-surface system for the condensate heating for the water/steam circuit, and in that the branch line branches off from the heat-recovery boiler upstream of the heating-surface system in the exhaust-gas-side direction of flow.

A method of operating an integrated power plant, comprising the steps of:

• providing an integrated power plant including a gas-turbine arrangement, said gas turbine arrangement including a compressor, a combustion chamber, and a gas turbine;
• flowing hot exhaust gases through a heat-recovery boiler downstream of the gas turbine to exit the power plant after having passed said heat recovery boiler;
• arranging a water/steam circuit with a steam generator fired separately by burning a carbon-containing fuel with fresh combustion air not being part of said hot exhaust gases of the gas turbine, said steam generator having a flue-gas NOx-reduction unit downstream of the steam generator;
• and
• branching off at the heat-recovery boiler a predetermined portion of the exhaust gases coming from the gas turbine arrangement and flowing through the heat-recovery boiler and adding it to upstream of the flue-gas NOx-reduction unit to the flue gases coming from the steam generator.