METHOD FOR OPERATING A POWER PLANT

Abstract

A contact arm and a method for a disconnect switch, having a profile body and a contact element in electrical contact with the profile body to establish electrical contact with a contact counterpart. The profile body has a first diameter parallel to the contact element. The contact element has a concave surface with a radius of curvature and is arranged on a side directed away from the profile body. The radius of curvature is smaller than the radius of curvature of a circle segment having the first diameter of the profile body. The method includes a contact element of the contact arm establishing electrical and/or mechanical contact with a contact counterpart. A concave surface of the contact element which is directed towards the contact counterpart has a radius of curvature, which is smaller than the radius of curvature of a circle segment having the maximum diameter of the contact element.

Claims

1.-8. (canceled)

9. A method for operating a power plant having a gas turbine, a heat recovery steam generator connected downstream of the gas turbine, a steam turbine connected to the heat recovery steam generator and an auxiliary burner arranged in the heat recovery steam generator, the method comprising: setting a target pressure value immediately upstream of the steam turbine, in order to achieve a predefined power plant capacity, wherein the target pressure value is a target value for the auxiliary burner.

10. The method as claimed in claim 9, wherein the target pressure value is deduced from a status of a primary control element.

11. The method as claimed in claim 10, wherein the primary control element is a gas turbine capacity.

12. The method as claimed in claim 9, wherein a heat store is employed as an auxiliary heat source and, if required, heat is released from the heat store.

13. The method as claimed in claim 10, wherein a change in the status of the primary control element is converted, by means of amplification, into a target pressure value variation, which is added to a current actual pressure.

14. The method as claimed in claim 9, wherein the auxiliary burner is only operated in the event that a target value for power plant capacity cannot be achieved or maintained by means of the gas turbine, within its control range, and the steam turbine alone.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] For exemplary purposes, the invention is described in greater detail with reference to the drawings. In the drawings, which are schematic and not to scale:

[0026] FIG. 1 shows a power plant, and

[0027] FIG. 2 shows the control system according to the invention, for operating the power plant.

DETAILED DESCRIPTION OF INVENTION

[0028] FIG. 1 shows a power plant 1 having a gas turbine 2, a heat recovery steam generator 3, a steam turbine 4 and an auxiliary burner 15 by way of an auxiliary heat source 5. The gas turbine 2 and the auxiliary burner 15 function as heat sources for the heat recovery steam generator 3 which is arranged downstream of the gas turbine 2, in which fresh steam is generated for the steam turbine 4. Heat can be introduced by means of a release from a heat store 14, alternatively or additionally to the auxiliary burner 15. The heat store 14, as represented, can thus be arranged within the heat recovery steam generator 3, but also externally thereto.

[0029] FIG. 2 shows the control system according to the invention for the power plant 1. During the operation of the power plant 1, the heat recovery steam generator 3 receives an input of heat 6 from the gas turbine 2 and, optionally, an input of heat 7 from the auxiliary heat source 5. An actual pressure value 8 is generated accordingly.

[0030] With respect to the gas turbine 2, the actual capacity 9 and the maximum capacity 10 are known. The difference between these values is determined. Optionally, particularly in isolated networks, it is still necessary for a reserve capacity to be maintained for network frequency-stabilizing measures, such that the in-service gas turbine 2 is not operated up to the technically feasible maximum capacity 10, but only up to a control range limit 11 which lies below the maximum capacity 10.

[0031] On the basis of a linear relationship between the steam flux (and the steam turbine capacity) and the pre-pressure only, by means of amplification 12, a target pressure value 13 for the steam pressure immediately upstream of the steam turbine 4 is determined on the basis of values for the gas turbine. This target pressure value is then employed, depending upon the capacity demand of the power plant 1, either as a target value for the gas turbine 2 or, in the event that the gas turbine 2 is already operating in the upper control range, for the auxiliary heat source 5.