METHOD FOR STARTING-UP AND SHUTTING-DOWN A GAS TURBINE IN A COMBINED GAS AND STEAM POWER PLANT

Abstract

Provided is a method for starting and stopping a gas turbine in a combined cycle power plan, wherein the gas turbine includes a compressor having adjustable guide vanes and the gas turbine power can also be controlled by opening the guide vanes. When the gas turbine is started, it is driven up to a base load or up to an emission-compliant load point, and the guide vanes are opened before the base load or the emission-compliant load point is reached.

Claims

1. A method for starting-up and shutting-down a gas turbine in a combined gas and steam power plant, wherein the gas turbine comprises a compressor having adjustable guide vanes, and the gas-turbine output power can also be controlled by opening of the guide vanes, wherein the gas turbine, when being started-up, is operated up to base load or up to an emission-compliant load point, wherein the guide vanes are opened before the base load or the emission-compliant load point is attained.

2. The method as claimed in claim 1, wherein the gas turbine ramped-up with a maximum possible load ramp.

3. The method as claimed in claim 1, wherein the guide vanes are closed at the beginning of the start-up operation.

4. The method as claimed in claim 1, wherein the guide vanes are opened as widely as possible, within the scope of the emission specifications.

5. The method as claimed in claim 1, wherein the combined gas and steam power plant comprises an exhaust-gas flue, and emissions are measured continuously in the exhaust-gas flue.

6. The method as claimed in claim 1, wherein temperature sensors are read out continuously during starting-up and shutting-down.

7. The method as claimed in claim 6, wherein the temperature sensors on thick-walled components are read out continuously, i.e. on components having an outer diameter to inner diameter ratio of greater than 1.2.

Description

BRIEF DESCRIPTION

[0020] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0021] FIG. 1 shows a schematic representation of a combined gas and steam power plant; and

[0022] FIG. 2 shows a graph of the electrical output power of the combined gas and steam power plant over the exhaust-gas temperature.

DETAILED DESCRIPTION

[0023] Shown in the schematic representation of FIG. 1 is a combined gas and steam power plant 2, having a gas turbine 1, a waste-heat steam generator 7 and a steam turbine 8. Other embodiments, such as, for example, two or more gas turbines, each having a downstream waste-heat steam generator, or even having a common waste-heat steam generator, are likewise possible.

[0024] The gas turbine 1 comprises a compressor 3, a combustion chamber 17 and a turbine 18. The compressor 3 comprises adjustable guide vanes 4, by means of which the compressor air mass flow can be set.

[0025] Downstream from the steam turbine 8, in a water-steam circuit 9, is a condenser 10. The water-steam circuit 9 additionally comprises the waste-heat steam generator 7, arranged in which, in particular on thick-walled components, are temperature sensors 6.

[0026] The steam turbine 8 usually comprises a plurality of pressure stages 11, which drive the generator 14, via a common shaft 12 that has a coupling 13.

[0027] For the purpose of supplying working fluid or flue gas, expanded in the gas turbine 1, into the waste-heat steam generator 7, there is an exhaust-gas line 15 connected to an input 16 of the waste-heat steam generator 7. The expanded working fluid from the gas turbine 1, i.e. the gas-turbine gas, exits the waste-heat steam generator 7 via an exhaust-gas flue 5.

[0028] FIG. 2 shows the electrical power output of the combined gas and steam power plant 2, represented over the exhaust-gas temperature, in the operating regime 19 of embodiments of the invention (two possible operating curves, indicated by broken line), in comparison with the former operating regime 20 (indicated by dotted line). In the case of the former operating regime 20, the guide vanes 4 remained closed until the gas turbine 1 was run up to base load or to an emission-compliant load point. This guaranteed a stable and emission-compliant combustion and, owing to the low exhaust-gas temperatures, as compared with present-day gas turbines 1, was the exemplary method. With the method according to embodiments of the invention, the mass flow through the gas turbine 1 is already increased before attaining the base load or an emission-compliant load point, as a result of which, inter alia, the temperature of the exhaust-gas flow is reduced.

[0029] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0030] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.