Method for cleaning and conditioning the water-steam circuit of a power plant, especially of a nuclear power plant

Patent metadata

Field	Value
Publication number	US-9943890-B2
Application number	US-201314104109-A
Country	US
Kind code	B2
Filing date	Dec 12, 2013
Priority date	Feb 28, 2012
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A method for cleaning and conditioning the water-steam circuit of a power plant, especially of a nuclear power plant, uses an amine as a film-forming agent. The amine is metered into the working medium circulating in the water-steam circuit. The film-forming agent forms a hydrophobic film on the surfaces of the circuit. During the process, the concentration of at least one impurity contained in the water and the concentration of the film-forming agent in at least in the feed water of the steam generator are measured and monitored. The concentration of the film-forming agent is varied, as needed, subject to the concentration of the impurity.

First claim

The invention claimed is:

1. A method of cleaning and conditioning a water/steam circuit of a power plant, the method comprising:
adding an amine as film-forming agent to a work medium circulating in the water/steam circuit during power operation, to cause the film-forming agent to form a hydrophobic film on the surfaces of the water/steam circuit;
monitoring a concentration of at least one impurity contained in the work medium by directly measuring the at least one impurity during a duration of the method and monitoring a concentration of the film-forming agent in a steam generator feed water by directly measuring the concentration of the film-forming agent during a duration of the method;
modifying the concentration of the film-forming agent depending on the directly measured concentration of the at least one impurity; and
decreasing a metering rate of the film-forming agent in the case of an increase in the directly measured concentration of the at least one impurity.

2. The method according to claim 1 , which comprises measuring the concentration of the film-forming agent and the concentration of the at least one impurity at a plurality of measurement points distributed over the water/steam circuit.

3. The method according to claim 1 , which comprises interrupting a metering-in of the film-forming agent if the concentration of the at least one impurity approaches a threshold value.

4. The method according to claim 1 , wherein at least one measurement point is disposed in a dual-phase region of the water/steam circuit and at least one measurement point is disposed in a one-phase region of the water/steam circuit.

5. The method according to claim 1 , which comprises carrying out the method in a nuclear power plant.

6. The method according to claim 1 , which further comprises purging the water/steam circuit.

7. The method according to claim 6 , which comprises purging the water/steam circuit directly following an interruption of a metering-in of the film-forming agent.

8. The method according to claim 1 , which comprises using a monoamine with a hydrocarbyl comprising 8 to 22 carbon atoms as the film-forming agent.

9. The method according to claim 8 , wherein the film-forming agent is octadecylamine.

10. The method according to claim 1 , which comprises metering-in the film-forming agent with such a rate that the concentration of the film-forming agent in a liquid phase of the work medium does not exceed a concentration of 2 ppm.

11. The method according to claim 10 , wherein a maximum concentration of the film-forming agent of at most 1.5 ppm.

12. The method according to claim 10 , which comprises terminating the metering-in of the film-forming agent when the concentration of the film-form ing agent has reached a value of 1 ppm to 2 ppm.

13. The method according to claim 10 , which comprises terminating the metering-in of the film-forming agent when the concentration of the film-forming agent has reached a value of 1 ppm to 1.5 ppm.

14. The method according to claim 10 , which comprises terminating the metering-in of the film-forming agent when the concentration of the film-forming agent at a constant metering rate remains constant, averaged over time, at a plurality of measurement points in the water/steam circuit.

15. The method according to claim 14 , wherein an unchanging concentration of film-forming agent is measured at a plurality of points distributed over the water/steam circuit.

Assignees

• Areva Gmbh

Inventors

• Ramminger Ute
• Fandrich Joerg
• Roumiguiere Fernando-Mario

Classifications

• G21C17/0225

  Chemical surface treatment, e.g. corrosion (corrosion prevention in presence of water from scale removal or by modification of the properties of the liquid C02F5/00; inhibiting corrosion by adding corrosion inhibitors C23F11/00) · CPC title

• G21C15/28

  Selection of specific coolants (if serving as the moderator G21C5/12; compositions per se C09K5/00; {organic coolants G21C5/123}); {Additions to the reactor coolants, e.g. against moderator corrosion (purification and regeneration of the reactor coolants G21C19/30)} · CPC title

• F22B37/483

  specially adapted for nuclear steam generators · CPC title

• F22B37/56

  Boiler cleaning control devices, e.g. for ascertaining proper duration of boiler blow-down · CPC title

• G21D1/00

  Details of nuclear power plant (control G21D3/00) · CPC title