Method for operating a steam power installation and corresponding steam power installation

• US 20040105518A1
• Filed: 09/12/2003
• Published: 06/03/2004
• Est. Priority Date: 03/15/2001
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Abel, Tilman, Haberberger, Georg, Riebeck, Imke, Blanck, Dieter
• Granted Patent: US 6,964,167 B2
• Time in Patent Office: Days
• US Class Current: 376/210
• CPC Class Codes: F01K 7/40 Use of two or more feed-water heaters in series

Abstract

The invention relates to a method for operating a steam power installation, whereby steam produced in a boiler is condensed in a condenser after passing through at least one turbine, and the condensate obtained is preheated and redirected back to the boiler as boiler feed-water. In order to preheat the condensate, said condensate is split into a first partial current and a second partial current. Only the first partial current is preheated and the second partial current is then mixed with the preheated first partial current. The power of the turbine can thus be increased as required, up to the boiler reserve of the steam power installation.

Claims

1. A method for operating a steam power installation (1), whereby steam (D) generated in a boiler (3) is condensed in a condenser (7) after flowing through at least one turbine (5), and the condensate (K) obtained is preheated and fed back to the boiler (3) as feed-water (S),

characterized in that the condensate (K) is divided for condensate preheating into a first partial flow (K₁) and a second partial flow (K₂), only the first partial flow (K₁) being preheated, and the second partial flow (K₂) being re-mixed with the preheated first partial flow (K₁).

2. The method as claimed in claim 1,

characterized in that the first partial flow (K₁) is preheated with bleeder steam (A₁,A₂) from the turbine (5).

3. The method as claimed in claim 1 or 2,

characterized in that the first partial flow (K₁) is preheated in at least two stages (9A,9B).

4. The method as claimed in claim 1, 2 or 3,

characterized in that a preheat temperature (Ts) of the boiler feed-water (S) of 210°

C. to 250°

C., in particular 220°

C. to 240°

C., is set for the mixing of the partial flows (K₁, K₂).

5. The method as claimed in one of the preceding claims,

characterized in that the first partial flow (K₁) and the second partial flow (K₂) are divided in the ratio 0.4 to 0.8, in particular in the ratio 0.6 to 0.7.

6. The method as claimed in one of the preceding claims,

characterized in that the division of the partial flows (K₁, K₂) is controlled or regulated.

7. The method as claimed in one of the preceding claims,

characterized in that after the mixing of the partial flows (K₁, K₂), the mixture is fed as boiler feed-water (S) to a fossil-fired steam generator.

8. A steam power installation (1) for implementing the method as claimed in one of the preceding claims, comprising a boiler (3) for generating steam (D), at least one turbine (5), a condenser (7) connected on the steam outlet side of the turbine (5), a condensate line (13) for feeding the condensate (K) back to the boiler (3), and a preheating device (15) connected in the condensate line (13) for preheating condensate (K),

characterized in that a bypass line (17) bypassing the preheating device (15) is provided so that the preheating device (15) only receives a first partial flow (K₁) of the condensate (K).

9. The steam power installation as claimed in claim 8,

characterized in that the preheating device (15) is connected to the turbine (5) via a bleeder line (19A,19B).

10. The steam power installation as claimed in claim 8 or 9,

characterized in that the bypass line (17) has a control valve (21) for regulating a second partial flow (K₂) of the condensate (K) that bypasses the preheating device (15).

11. The steam power installation as claimed in claim 8, 9 or 10,

characterized in that the bypass line (17) flows into the condensate line (13) downstream of the preheating device (15).

12. The steam power installation as claimed in one of the claims 8 to 11,

characterized in that the preheating device (15) has at least one heat exchanger (23A,23B), in particular a high-pressure preheater.

13. The steam power installation as claimed in one of the claims 8 to 12,

characterized in that a diversion line (27) that can be activated by a quick-shutoff fitting (25) is connected in parallel with the preheating device (15).