JP4859955B2 - Method and apparatus for searching for leak location of condenser cooling pipe - Google Patents

Description

  The present invention relates to a search method and a search device for a leak cooling pipe of a condenser. In particular, the present invention relates to a method and a search device for searching for a position in the height direction of a leakage cooling pipe among a large number of cooling pipes for condensing turbine steam inside a condenser.

  In general, in a thermal power plant, a turbine is rotated by steam generated by a boiler or the like, and electric power is generated by a generator connected to the turbine. The condenser cools and condenses the water vapor after operating the turbine, and returns it to a low-pressure saturated liquid (condensate). For example, this condensate is reused as turbine steam.

  The condenser is configured such that the cooling water does not come into direct contact with the turbine steam. And the condenser is comprised with the robust box-shaped container (it is called a trunk | drum or a trunk | drum part). A large number of cooling pipes pass through the body portion. And by making cooling water pass through these cooling pipes, the vapor | steam inside a trunk | drum can be cooled and condensed.

  By the way, when seawater is used as cooling water, corrosion of the cooling pipe is induced, and seawater may leak from the corroded portion of the cooling pipe and may be mixed in the condensate inside the condenser. Therefore, it is necessary to constantly monitor the leakage of seawater from the cooling pipe. In addition, it is necessary to identify a cooling pipe from which seawater leaks from a large number of cooling pipes, and to repair or replace the corresponding cooling pipe.

  As a method for identifying a cooling pipe through which seawater leaks, a method for identifying a leakage cooling pipe capable of quickly and reliably identifying a condenser cooling pipe without stopping the turbine is disclosed ( For example, see Patent Document 1).

  The method for specifying a condenser cooling pipe of Patent Document 1 includes a seawater discharge process, a film sticking process, and a leak determination process. In the seawater discharging step, seawater is discharged from one of the inlet side water chamber and the outlet side water chamber of the condenser, or from the other inlet side water chamber and outlet side water chamber. In the film sticking step, a predetermined wrap film is stuck on one or the other inlet-side water chamber from which the seawater has been discharged, or on the tube opening of the cooling pipe in the tube plate of the one or the other outlet-side water chamber. In the leakage determination step, it is determined that the cooling pipe is a leakage pipe when the shape of the wrap film at the pipe opening changes to a predetermined state.

  In addition, as a method of identifying the cooling pipe through which seawater leaks, the inside of the condenser is filled up to the uppermost stage of the cooling pipe, and then a fluorescent agent is introduced, and the cooling pipe of one of the water chambers is opened. It is also carried out that the cooling pipe is determined to be a leakage cooling pipe by detecting the fluorescent agent.

  These identification methods are inefficient because it takes a long time to identify a leaky cooling pipe when the number of cooling pipes becomes as large as about 10,000. Therefore, an efficient condenser seawater leakage position searching method for searching the position in the height direction of the cooling pipe where seawater leaks into the condenser, and then examining the leakage cooling pipe at that position, and An apparatus is disclosed (for example, see Patent Document 2).

  In the condenser seawater leakage position search method according to Patent Document 2, when seawater leakage occurs in the condenser, the water level of the seawater in the water chamber is gradually changed while detecting seawater in the condensate. The seawater leakage position is searched by measuring the water surface height in the water chamber when the water is detected.

JP 2008-106985 A JP-A-51-90873

  However, the seawater leakage position search method for a condenser according to Patent Document 2 samples the condensate stored in the lower part of the fuselage (so-called hot well), and determines the conductivity of the sampled condensate. Measured with a conductivity meter to detect seawater contamination in the condensate.

  Accordingly, the seawater leaked from the cooling pipe is dropped into the hot well, and then the dripped seawater diffuses into the condensate, so there is a problem that it takes a considerable time to detect an abnormal value with the conductivity meter. . That is, the measurement system according to Patent Document 2 has a problem that the time (response speed) until the search for the leakage cooling pipe is slow.

  If a method and a search device for a leak position of a condenser pipe in a condenser can be realized, the time until the search for a leak cooling pipe can be realized. The above can be said to be the subject of the present invention.

  The present invention has been made in view of such problems, and provides an efficient method and apparatus for searching for a leakage position of a condenser condenser cooling pipe, which has a fast time to search for a condenser condenser condenser. The purpose is to do.

  In order to achieve the above object, the present inventors can solve the above-mentioned problems by maintaining the inside of the condenser in a vacuum state and circulating an inert gas through the cooling chamber through the water chamber. Based on this finding, the inventors have invented the following search method and search device for the leakage position of the condenser condenser of the condenser.

  (1) According to the present invention, there is provided a method for searching for a leak position of a condenser cooling pipe, which passes through a body part, a pair of water chambers disposed on both wings of the body part, and the inside of the body part, A method for searching for a leakage position of a cooling pipe of a condenser having a plurality of cooling pipes that are supplied with cooling water from a water chamber and discharged into the other water chamber. A vacuum state maintaining step for evacuating and maintaining the inside of the body portion in a vacuum state, a water filling step for filling the pair of water chambers with cooling water, and injecting an inert gas into one of the water chambers , A water level changing step for changing the level of the cooling water in one of the water chambers, a measuring step for detecting leakage of the inert gas from the exhaust of the body part, and detecting the inert gas in this measuring step When checking the water level of one of the water chambers Comprising a searching step of searching the position in the height direction of the 却管, the.

  (2) It is preferable that the body part is arranged with a pair of water chambers in two sets.

  (3) The inert gas preferably contains helium.

  (4) According to the present invention, there is provided an apparatus for searching for a leak position of a condenser cooling pipe penetrating through a fuselage, a pair of water chambers disposed on both wings of the fuselage, and the interior of the fuselage. An apparatus for searching for a leakage position of a condenser cooling pipe comprising a plurality of cooling pipes that are supplied with cooling water from a water chamber and discharged into the other water chamber. Exhaust means for evacuating and maintaining the inside of the body portion in a vacuum state, inert gas supply means for injecting an inert gas into one of the water chambers, and injecting an inert gas into one of the water chambers However, the level of the cooling water in one of the water chambers is changed from a full state, and the water level measuring means for measuring the water level of the one of the water chambers and the leakage of the inert gas from the exhaust of the body part are detected. Measuring means for detecting the inert gas when the measuring means detects the inert gas. The measures the water level in the water chamber to find the position in the height direction of the cooling tube.

  (5) The exhaust means preferably includes a vacuum pump.

  (6) Preferably, the inert gas includes helium, and the inert gas supply means includes a cylinder for compressing and storing helium.

  In the method of searching for the leakage position of the condenser cooling pipe according to the present invention, since the inert gas flowing into the fuselage from the leakage cooling pipe is immediately detected in the measurement step, the leak cooling pipe is searched. Time is fast and efficient.

  Further, the apparatus for searching for a leak position of a condenser cooling pipe according to the present invention can detect the inert cooling gas flowing into the body part from the leak cooling pipe immediately by the measuring means. Is fast and efficient.

It is a systematic diagram which shows the structure of the condenser by one Embodiment of this invention. It is a perspective view which shows the structure of the condenser by the said embodiment, and has shown the condenser and a pair of water chamber with the longitudinal cross-section. It is a flowchart which shows the procedure of the search method of the leak position of the cooling pipe of the condenser by one Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  Initially, the structure of the condenser by one Embodiment of this invention is demonstrated. FIG. 1 is a system diagram showing the configuration of a condenser according to an embodiment of the present invention. FIG. 2 is a perspective view showing the configuration of the condenser according to the embodiment, and shows the condenser and a pair of water chambers in a longitudinal section.

  Referring to FIG. 1 or FIG. 2, the condenser 10 is composed of a robust box-shaped body portion 1. A pair of water chambers 2 a and 2 b and a pair of water chambers 2 c and 2 d are arranged on both wings of the body portion 1. In addition, a plurality of cooling pipes 3 penetrate through the body portion 1.

  Referring to FIG. 1 or FIG. 2, a supply pipe 21a is connected to the lower part of the water chamber 2a. Seawater W serving as cooling water is supplied to the supply pipe 21a through the on-off valve 22a. And the seawater W can be supplied to the water chamber 2a.

  On the other hand, referring to FIG. 1 or FIG. 2, a drain pipe 21b is connected to the lower part of the water chamber 2b. Seawater W inside the water chamber 2b is discharged to the drain pipe 21b through the on-off valve 22b. That is, the seawater W circulated from the water chamber 2a through the plurality of cooling pipes 3 can be discharged.

  Similarly, referring to FIG. 1 or FIG. 2, a supply pipe 21c is connected to the lower part of the water chamber 2c. Seawater W serving as cooling water is supplied to the supply pipe 21c via the on-off valve 22c. And the seawater W can be supplied to the water chamber 2c.

  Similarly, referring to FIG. 1 or FIG. 2, a drain pipe 21d is connected to the lower part of the water chamber 2d. Seawater W inside the water chamber 2d is discharged to the drain pipe 21d through the on-off valve 22d. That is, the seawater W circulated from the water chamber 2c through the plurality of cooling pipes 3 can be discharged.

  If FIG. 1 or FIG. 2 is referred, the inside of the trunk | drum 1 and the water chamber 2a are isolated by the tube sheet 3a. One tube port 31a of the cooling tube 3 opens in the tube plate 3a toward the water chamber 2a. Moreover, the inside of the trunk | drum 1 and the water chamber 2b are isolated by the tube sheet 3b. The other tube port 31b of the cooling tube 3 opens to the tube plate 3b toward the water chamber 2b.

  Referring to FIG. 1 or FIG. 2, since both ends of the cooling pipe 3 are open toward the water chamber 2 a and the water chamber 2 b, the seawater W can be circulated through the cooling pipe 3. Moreover, the cooling pipe 3 can also distribute | circulate the water chamber 2a and the water chamber 2b with a compressive fluid (gas). In addition, although the same tube sheet is provided also in the water chamber 2c and the water chamber 2d, since an effect | action is the same, description is omitted.

  As described above, referring to FIG. 1 or FIG. 2, the condenser 10 allows the steam inside the trunk portion 1 to pass through by passing the seawater W, which is also called a tube nest, through the plurality of cooling pipes 3 as cooling water. Can cool and condense.

  Referring to FIG. 1 or FIG. 2, a retention portion (so-called hot well) 11 for storing condensed condensate is provided at the lower portion of the condenser 10. Furthermore, an outlet 12 of the condenser 10 is provided at the bottom of the staying part 11. A recovery pipe 12 a is connected to the outlet portion 12. Condensate is recovered by a condensate pump 13 provided in the recovery pipe 12a, and most of the condensate is reused as turbine steam.

  Referring to FIG. 1 or FIG. 2, high-pressure steam and medium-pressure steam generated in a boiler (not shown) may be supplied from the upper portion of the condenser 10 via the bypass pipes 16 and 17.

  Referring to FIG. 1 or FIG. 2, the staying part 11 is provided with a partition plate 14 and partitioned into a first staying part 14a and a second staying part 14b. The first staying part 14a and the second staying part 14b are each provided with a salt meter 15. The salt meter 15 can detect the salt concentration in the condensate of the first retention part 14a and the second retention part 14b.

  Referring to FIG. 1 or FIG. 2, when the salt meter 15 provided in the first staying part 14a detects an abnormal value, a plurality of cooling pipes 3 (first cooling pipes) disposed above the first staying part 14a are detected. It can be estimated that leakage of seawater W has occurred in any of the tube groups.

  On the other hand, referring to FIG. 1 or FIG. 2, when the salt meter 15 provided in the second staying part 14b detects an abnormal value, a plurality of cooling pipes 3 (the first pipes disposed above the second staying part 14b). It can be estimated that the leakage of seawater W has occurred in any of the two cooling pipe groups.

  Thus, the retention part 11 which stores condensate is divided into the 1st retention part 14a and the 2nd retention part 14b, and it is the salt meter 15 provided in each of the 1st retention part 14a and the 2nd retention part 14b. By monitoring the abnormal value, it can be estimated that leakage of seawater W has occurred in either the first cooling pipe group or the second cooling pipe group. That is, the presence of the leakage cooling pipe can be distinguished from either the first cooling pipe group or the second cooling pipe group among all the cooling pipes 3.

  Next, the structure of the search device for the leak position of the condenser cooling pipe according to the embodiment of the present invention will be described.

  Referring to FIG. 1 or FIG. 2, a search device 100 according to an embodiment of the present invention includes a vacuum pump 4 serving as an exhaust unit. The vacuum pump 4 can exhaust the inside of the body part 1 and maintain the inside of the body part 1 in a vacuum state.

  Also, referring to FIG. 1 or FIG. 2, the search device 100 includes a cylinder 5 serving as an inert gas supply means. In the embodiment, the cylinder 5 stores helium compressed.

  Referring to FIG. 1 or FIG. 2, the cylinder 5 is connected to the upper part of the water chamber 2a via the on-off valve 5a. When the on-off valve 5a is opened, helium can be supplied to the water chamber 2a. Moreover, the cylinder 5 is connected to the upper part of the water chamber 2c through the on-off valve 5b. When the on-off valve 5b is opened, helium can be supplied to the water chamber 2b.

  Referring to FIG. 1 or FIG. 2, the search device 100 includes a liquid level gauge 6 serving as a water level measuring means. A plurality of liquid level sensors 6a are arranged in the height direction inside the water chamber 2b. The plurality of liquid level sensors 6a constitute an electric circuit with reference to the lowest level liquid level sensor 6a. The liquid level gauge 6 can measure the liquid level inside the water chamber 2b by converting it into an electric signal.

  Similarly, a plurality of liquid level sensors 6a are arranged in the height direction inside the water chamber 2d. The liquid level gauge 6 can measure the level of the liquid level inside the water chamber 2d by converting it into an electrical signal.

  Referring to FIG. 1 or FIG. 2, the search apparatus 100 includes a gas detector (so-called helium leak detector) 7 that serves as a measuring means for detecting helium. The gas detector 7 is connected to the exhaust port of the vacuum pump 4. The gas detector 7 can detect leaked helium by measuring the concentration of helium inside the body portion 1 via the vacuum pump 4.

  Next, the operation of the search device 100 according to the embodiment of the present invention will be described.

  Referring to FIG. 1, the water chamber 2a is filled with seawater W in advance. That is, the water chamber 2b is also full of seawater W. Next, helium is supplied into the water chamber 2a while discharging the seawater W from the water chamber 2b. And when helium is detected by the gas detector 7, the leakage cooling pipe in the height direction can be searched from the first cooling pipe group by checking the water level of the water chamber 2b by the liquid level sensor 6a.

  On the other hand, referring to FIG. 1, the water chamber 2c is filled with seawater W in advance. That is, the water chamber 2d is also full of seawater W. Next, helium is supplied into the water chamber 2c while discharging the seawater W in the water chamber 2d. And when helium is detected by the gas detector 7, the leakage cooling pipe in the height direction can be searched from the second cooling pipe group by checking the water level of the water chamber 2d with the liquid level sensor 6a.

  As described above, in the apparatus for searching the leakage position of the condenser cooling pipe according to the present invention, the helium flowing into the body portion 1 from the leakage cooling pipe is immediately detected by the gas detector 7. The time to search is fast and efficient.

  Next, a method for searching for a leakage position of a condenser cooling pipe according to an embodiment of the present invention will be described. FIG. 3 is a flowchart showing a procedure of a method for searching for a leak position of a condenser cooling pipe according to an embodiment of the present invention.

  Referring to FIG. 1 and FIG. 2, the retrieval device 100 is used in the method for retrieving the leakage position of the condenser cooling pipe according to the embodiment of the present invention. In the following procedure, a description will be given assuming that a leakage cooling pipe exists in the first cooling pipe group connecting the water chamber 2a and the water chamber 2b.

  Referring to FIG. 3, first, the vacuum pump 4 is driven to evacuate the interior of the body portion 1 and maintain the interior of the body portion 1 in a vacuum state (step S <b> 1). Next, the water chamber 2a and the water chamber 2b are filled with seawater W as cooling water (step S2).

  Referring to FIG. 3, next, an inert gas is injected into the water chamber 2a (step S3). Next, the water level of the water chamber 2a and the water chamber 2b is changed by discharging the seawater W of the water chamber 2b (step S4). In the process of changing the water level in step S4, the water level in the water chamber 2b is measured by the liquid level gauge 6.

  Referring to FIG. 3, next, helium in the exhaust of the body part 1 is measured using the gas detector 7 (step S5). Next, when an abnormal value is detected by the gas detector 7 (step S6), the injection of helium into the water chamber 2a is stopped (step S7).

  Referring to FIG. 3, next, the discharge of the seawater W from the water chamber 2b is stopped (step S8), and the water level in the water chamber 2b is checked with the liquid level gauge 6, thereby increasing the height of the first cooling pipe group. Since the leakage cooling pipe can be searched in the direction, the series of procedures is completed.

  Referring to FIG. 3, the procedure from step S3 to step S5 proceeds until an abnormal value is detected by the gas detector 7 in step S6.

  In the method of searching for the leakage position of the condenser cooling pipe according to the embodiment of the present invention, the helium flowing into the body part 1 from the leakage cooling pipe is immediately detected by the gas detector 7, so that the leakage cooling pipe search is performed. The time to reach is fast and efficient.

  Referring to FIG. 2, in the method of searching for the leak position of the condenser cooling pipe according to the embodiment of the present invention, the body 1 is arranged in two pairs of water chambers 2 a, 2 b and 2 c, 2 d. Yes. And the trunk | drum 1 is divided into the 1st retention part 14a and the 2nd retention part 14b. Furthermore, since the 1st retention part 14a and the 2nd retention part 14b are each provided with the salt test meter 15, either the 1st cooling pipe group or the 2nd cooling pipe group is selected from among all the cooling pipes 3. The presence of leaked cold water pipes can be confirmed.

  Furthermore, the method for searching for the leak position of the condenser cooling pipe according to the embodiment of the present invention uses the inert gas helium for searching the leaking cold water pipe. Helium has the advantages that it is chemically inert and, under normal conditions, has no danger of combustion or explosion and is not toxic. Helium is particularly lighter than air and is suitable for searching for leaky cooling pipes. Note that nitrogen or argon may be used as the inert gas.

  After the position in the height direction of the leak cooling pipe is searched, the search method and search apparatus for the leak position of the condenser cooling pipe according to the embodiment of the present invention, as disclosed in Patent Document 1, When a wrap film is affixed to the horizontal pipe opening at the position and the shape of the wrap film changes to a predetermined state, the leakage cooling pipe can be specified. Therefore, the search method and search device for the leak position of the condenser cooling pipe according to the embodiment of the present invention can shorten the working time in a narrow water chamber.

  In addition, according to the embodiment of the present invention, the method and apparatus for searching the leakage position of the condenser cooling pipe is searched for the inside of the condenser after the position in the height direction of the leakage cooling pipe is searched. After the water is filled up to that position, the fluorescent agent is introduced, and the fluorescent agent is detected from the outlet of the cooling pipe of one of the water chambers, so that the cooling pipe can be specified as the leakage cooling pipe. Therefore, the search method and search device for the leakage position of the condenser cooling pipe according to the embodiment of the present invention can reduce the amount of the fluorescent agent used, and can also reduce the solvent for treating the fluorescent agent.

  Furthermore, the method and apparatus for searching for a leak position of a condenser cooling pipe according to an embodiment of the present invention can fill the water chamber using existing equipment, thereby reducing the work time. Further, since helium is used as the detection gas, work safety can be ensured.

DESCRIPTION OF SYMBOLS 1 Body part 2a * 2b, 2c * 2d A pair of water chamber 3 Cooling pipe 4 Vacuum pump (exhaust means)
5 cylinder (inert gas supply means)
6 Level gauge (water level measuring means)
7 Gas detector (measuring means)
10 Condenser W Seawater (cooling water)

Claims (4)

The body part, a pair of water chambers arranged on both wings of the body part, and the interior of the body part are supplied with cooling water from one of the water chambers, and the cooling water is discharged into the other water chamber. A method for retrieving a leakage position of a condenser cooling pipe having a plurality of cooling pipes,
A vacuum state maintaining step of exhausting the inside of the body part from an exhaust port opened at the top of the body part using an exhaust means, and maintaining the inside of the body part in a vacuum state;
A full water step for filling the pair of water chambers with cooling water;
A water level changing step for changing the water level of the cooling water in the other water chamber while injecting helium into the one water chamber;
A measurement step in which a gas detector directly connected to an exhaust port of the exhaust means detects leakage of the helium from the exhaust of the body part without returning the helium to the body part ;
In this measurement step, when the gas detector detects the helium , the water level of the other water chamber is confirmed, and a search step for searching the position in the height direction of the cooling pipe where the cooling water leaks ; To find the leak location of condenser cooling pipes including   The method for searching for a leakage position of a condenser cooling pipe according to claim 1, wherein the body portion has a pair of water chambers arranged in two sets. The body part, a pair of water chambers arranged on both wings of the body part, and the interior of the body part are supplied with cooling water from one of the water chambers, and the cooling water is discharged into the other water chamber. An apparatus for searching a leakage position of a condenser cooling pipe comprising a plurality of cooling pipes,
Exhaust means for exhausting the interior of the body portion from an exhaust port opened at an upper portion of the body portion, and maintaining the interior of the body portion in a vacuum state;
An inert gas supply means for injecting helium into one of the water chambers;
A water level measuring means for measuring the water level of the other water chamber by injecting helium into one of the water chambers, changing the level of the cooling water in the other water chamber from a full water state,
Measuring means for detecting leakage of the helium from the exhaust of the body part,
The inert gas supply means includes a cylinder for compressing and storing helium,
The measurement means includes a gas detector directly connected to an exhaust port of the exhaust means without the helium returning to the body portion,
When the gas detector detects the helium, the water level of the other water chamber is measured to find the position in the height direction of the cooling pipe where the cooling water leaks. Search device. 4. The apparatus for searching for a leak position of a condenser cooling pipe according to claim 3, wherein said exhaust means includes a vacuum pump.

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