Condenser operation with isolated on-line test loop

• US 5,060,600 A
• Filed: 08/09/1990
• Issued: 10/29/1991
• Est. Priority Date: 08/09/1990
• Status: Expired due to Term

• Current Assignee: Texas Utilities Electric Co. (Sempra)
• Original Assignee: Texas Utilities Electric Co. (Sempra)
• Inventors: Brown, David S., Baum, W. Cave
• Primary Examiner(s): Favors, Edward G.
• Application Number:
  US07/566,222
• Time in Patent Office: 446 Days
• Field of Search: 122/379, 122/504, 122/401, 134/22.13, 134/22.14, 134/22.11, 134/170, 165/1, 165/95
• US Class Current: 122/379
• CPC Class Codes: F01K 21/06 Treating live steam, other than thermodynamically, e.g. for fighting deposits in engine
• CPC Class Codes: F22D 11/006 Arrangements of feedwater cleaning with a boiler
• CPC Class Codes: F28B 1/02 using water or other liquid as the cooling medium
• CPC Class Codes: F28B 11/00 Controlling arrangements with features specially adapted for condensers control arrangements in general G05

Abstract

A condenser structure wherein both ends of at least one tube, which is physically located among the other (numerous) tubes of the condenser'"'"'s tube bundles, is not connected to the inlet water box nor to the outlet water box; instead, this tube is provided with separate inlet and outlet connections. The separate inlet connection is preferably provided with a separately-controlled admixture of water treatment chemicals. Also disclosed is an innovative method of operating a steam condenser. One or more tubes, which are physically located among the other (numerous) tubes of the condenser, are isolated to provide a real-time test loop. The tube thus isolated is chosen to be among the tubes with the highest heat load, so that this tube provides a worst-case proxy for scaling in the other condenser tubes. The isolated tube is frequently inspected for scaling (e.g. at intervals of a week or so), and addition of anti-scaling chemicals to the cooling water is controlled with reference to the scaling (or lack thereof) seen in the isolated tube. Preferably the level of treatment chemicals is held at a lower level in the isolated test loop than in the primary cooling water supply.

Claims

1. A condenser system, comprising:

at least one bundle of tubes;

an inlet water box, connected to a first source of cooling water, and connected to the interiors of plural ones of said tubes;

an outlet water box, connected to the interiors of plural ones of said tubes;

a drain, connected to drain water from said outlet water box;

a steam manifold, connected to pass depleted steam over the exterior of said tubes in said bundle of tubes, whereby said steam is cooled and condensed by contact with said bundle of tubes;

a condensate removal path, connected to drain condensed steam from the exterior of said bundle of tubes;

wherein said bundle of tubes includes at least one monitoring tube, and said monitoring tube

has an interior which is isolated from the water flow in both of said water boxes and which can be viewed through an endoscopic probe without shutting down said first source of cooling water,

has a first end connected to a second source of cooling water, and

has a second end connected to a water drain;

whereby scale deposition on the interior of tubes ins aid tube bundle can be assessed by monitoring scale deposition on the interior of said monitoring tube.

4. The condenser system of claim 1, further comprising:

a first treatment chemical admixture point, connected to controllably introduce chemicals into said first source of cooling water; and

a second water treatment chemical admixture point, connected to controllably introduce chemicals into said second source of cooling water.

5. The condenser of claim 1, wherein less than 10% of the tubes within said bundle of tubes have respective interiors which are isolated from both of said water boxes.

6. The condenser of claim 1, wherein said bundle of tubes comprises more than 100 of said tubes.

7. The condenser of claim 1, wherein said bundle of tubes comprises more than 1000 of said tubes.

8. The condenser of claim 1, wherein said tubes in said bundle of tubes are all mounted substantially horizontally.

2. A steam-powered electrical generating plant, comprising:

a heat source;

a feedwater source;

a boiler, connected to receive feedwater from said feedwater source and to thermally couple said feedwater to a heat source so that said feedwater is at least partially converted into live steam;

at least one steam-powered motor, connected to receive steam from boiler and to partially convert the energy of said steam into mechanical motion;

at least one generator, connected to be powered by the mechanical motion of said motor, and to partially convert the energy of said mechanical motion into electricity;

a condenser, comprising;

at least one bundle of tubes;

an inlet water box, connected to a first source of cooling water, and connected to the interiors of plural ones of said tubes;

an outlet water box, connected to the interior of plural ones of said tubes;

a drain, connected to drain water from said outlet water box;

a steam manifold, connected to receive depleted steam from said motor, and to pass said depleted steam over the exterior of said tubes in said bundle of tubes, whereby said depleted steam is cooled and condensed by contact with said bundle of tubes;

a condensate removal path, connected to drain condensed steam from the exterior of said bundle of tubes;

wherein said bundle of tubes includes at least one monitoring tube, and said monitoring tube

has an interior which is isolated from both of said water boxes and which can be viewed through an endoscopic probe without shutting downsaid first source of cooling water,

has a first end connected to a second source of cooling water, and

has a second end connected to a water drain;

whereby scale deposition on the interior of tubes in said tube bundles can be assessed by monitoring scale depostion on the interior of said monitoring tube.

9. The generating plant of claim 2, wherein said heat source comprises a combustion chamber.

10. The generating plant of claim 2, wherein said boiler is heated by combustion.

11. The generating plant of claim 2, wherein said condenser includes exactly two of said tube bundles.

12. The generating plant of claim 2, wherein said outlet water box is connected so that at least some water from said outlet water box is pumped back to said inlet water box of said condenser.

13. The generating plant of claim 2, wherein said outlet water box is connected so that at least some water from said outlet water box is pumped through a cooling unit and back to said inlet water box of said condenser.

14. The generating plant of claim 2, wherein said motor comprises at least one steam turbine.

15. The generating plant of claim 2, wherein said motor consists essentially of multiple steam turbine stages.

16. The generating plant of claim 2, wherein said motor comprises a high-pressure steam turbine and a low-pressure steam turbine.

17. The generating plant of claim 2, wherein said motor comprises a high-pressure steam turbine and a low-pressure steam turbine, and wherein steam exhausted from said high-pressure steam turbine is reheated at some point between the exhaust of said high-pressure steam turbine and the inlet of said low-pressure steam turbine.

18. The generating plant of claim 2, wherein said motor comprises a high-pressure steam turbine and a low-pressure steam turbine and at least one additional turbine stage between said high-pressure steam turbine and said low-pressure steam turbine, and wherein steam exhausted from said high-pressure steam turbine is reheated at some point between the exhaust of said high-pressure steam turbine and the inlet of said low-pressure steam turbine.

19. The generating plant of claim 2, wherein said motor comprises a high-pressure steam turbine, an intermediate-pressure steam turbine, and a low-pressure steam turbine.

20. The generating plant of claim 2, wherein said feedwater source is connected to receive condensate from said condensate removal path.

3. A method for operating a steam condenser, comprising the steps of:

providing a condenser including at least one bundle of at least 1000 condenser tubes, wherein said bundle of tubes includes at least one monitoring tube, and said monitoring tube

has an interior which is isolated from both of said water boxes and which can be viewed through an endoscopic probe without shutting down said first source of cooling water,

has a first end connected to a second source of cooling water, and

has a second end connected to a water drain;

continually flowing cooling water, through the interior of said condenser tubes, from an inlet water box to an outlet water box;

continually flowing depleted steam across the exterior of said condenser tubes;

repeatedly, from time to time, monitoring said monitoring tube for degradation;

and admixing water treatment chemicals into said cooling water substantially continually, but only to the extent to which said step of monitoring said monitoring tube for degradation indicates that treatment is necessary to avoid degradation of said tubes of said bundle.