JP5415466B2 - How to identify condenser condenser leak condenser - Google Patents

Description

  The present invention relates to a method for identifying a condenser cooling pipe of a condenser, and more particularly to a method for improving its working efficiency.

Conventionally, thermal power plants and nuclear power plants have a water circulation system using a turbine coupled to a generator. For example, this circulation system has a structure in which water is heated by a boiler to form steam, and this steam is ejected to the turbine to rotate the turbine. And the steam after rotating a turbine is condensed by the condenser which uses seawater as cooling water, and is condensed. And this condensate is made into steam by being heated again by the boiler, and is again ejected to the steam turbine.
That is, in a thermal power plant or nuclear power plant, steam is condensed by a condenser using seawater as cooling water, and the condensed water is circulated in the power plant as circulating water.
In power plants such as those described above, seawater may leak from the cooling pipes that distribute the seawater for cooling. In this case, seawater enters the condenser and seawater enters the condensate. There was a case.
And since condensate circulates in the power plant, it may cause corrosion in the power plant components and piping, which is not preferable. For this reason, in a power plant, whether seawater is leaking inside the condenser is an important issue, and the presence or absence of seawater leakage to the condensate is constantly monitored.
In addition, if seawater leakage to condensate is detected, it is necessary to repair the cooling pipe for seawater leakage immediately. Several methods for identifying tubes are disclosed.

Patent Document 1 discloses an invention relating to a method for identifying a leakage cooling pipe of a condenser under the name of “a method for identifying a leakage cooling pipe of a condenser”.
The invention disclosed in Patent Document 1 includes a seawater discharging step of discharging seawater from one inlet side and outlet side water chamber of the condenser having a pair of water chambers, or from the other inlet side and outlet side water chamber, A film sticking step for sticking a predetermined wrap film to the inlet of the cooling pipe in the tube plate of one or the other inlet side water chamber or the one or the other outlet side water chamber from which the seawater has been discharged, and the wrap film of the pipe mouth A leakage determination step of determining that the cooling pipe is a leakage pipe when the shape of the cooling pipe changes to a predetermined state.
According to the invention disclosed in Patent Document 1 having the above-described configuration, it is possible to quickly and reliably identify the leakage cooling pipe of the condenser without stopping the turbine of the power plant.

Patent Document 2 describes a method of determining the presence or absence of leakage of a cooling pipe in a condenser having the name “condenser cooling pipe leakage determination method”, which cools steam used in a steam turbine or the like and condenses the steam. An invention related to this is disclosed.
If the invention disclosed in Patent Document 2 is described using the reference numerals used in the document as they are, the supply of cooling water to the first cooling pipe group 15A to be determined is stopped, and the inside of the body portion 13 is stopped. Is filled with water 30 in which the fluorescent paint is dissolved, the black light 31 is irradiated from the end into the first cooling tube group 15A, and the black light 31 is irradiated in the cooling tube 14 to be dissolved in the water 30. The presence or absence of water leakage in the cooling pipe 14 is determined based on whether or not the emission of the fluorescent paint can be confirmed.
According to the invention disclosed in Patent Document 2 having the above-described configuration, by filling the body portion with water mixed with the fluorescent paint, water containing the fluorescent paint enters the leakage cooling pipe, and there is a leakage point in the cooling pipe. In some cases, when each of the cooling pipes is irradiated with black light, the fluorescent paint contained in the water that has entered the cooling pipes emits light, so that the presence or absence of water leakage can be easily determined.

JP 2008-106985 A JP 2009-133568 A

Conventionally, it has been necessary to stop the turbine in order to identify the seawater leakage point in the condenser pipe of the condenser. On the other hand, according to the invention disclosed in Patent Document 1, it is possible to specify a cooling pipe in which seawater leaks without stopping the turbine, and in this respect, work efficiency can be greatly improved. did it.
However, in the invention disclosed in Patent Document 1, all of the seawater in the inlet-side water chamber and the outlet-side water chamber corresponding to the inlet / outlet of seawater that is cooling water is extracted, and all the cooling pipes provided in the tube plate are provided with the inlets. It is necessary to stretch the wrap film and observe the change in its surface. Usually, since there are many tube ports, the operation of attaching the wrap film to all the tube ports is extremely complicated.
For example, in the pipe group arranged in the tube plate that supports the cooling pipe in the condenser, there is a leakage cooling pipe in the bottom row in the horizontal arrangement row, and wraps sequentially from the top horizontal arrangement row in all the pipe group. When pasting a film and specifying a leakage cooling pipe, as a result, the work of sticking a wrap film to the majority of pipe ports is wasted, and there is a problem that it is difficult to improve work efficiency.

  In the case of the invention disclosed in Patent Document 2, although it is not necessary to perform the operation of attaching the wrap film to the pipe opening, it is necessary to fill the body of the condenser with water in which the fluorescent paint is dissolved, After specifying, the operation | work which drains the water with a fluorescent paint from the fuselage | body part, and wash | cleans the inside of a fuselage | body part and the surface of a cooling pipe group etc. was complicated.

  The present invention has been made in response to such a conventional situation, and the purpose of the present invention is to observe a change in the surface of a condenser with a wrap film stretched over the inlet of a cooling pipe without stopping the turbine. In the condenser leakage pipe identification method for identifying the condenser pipe where seawater is leaking, a part of the pipe group including the outlet of the condenser pipe is accurately extracted and wrapped in the pipe group. An object of the present invention is to provide a condenser cooling pipe identifying method for a condenser pipe that can reliably identify the outlet of the condenser condenser by simply attaching a film.

In order to achieve the above object, the condenser cooling pipe specifying method according to the first aspect of the present invention allows seawater used as cooling water to condense the steam discharged from the steam turbine to pass therethrough, and a plurality of cooling pipes One and the other cooling pipe group, a body part in which the cooling pipe group is disposed, one and other inlet side water chambers for supplying seawater to the cooling pipe, and one for receiving seawater that has passed through the cooling pipe and A pair of tube plates for fixing the other outlet-side water chamber, both ends of the cooling pipe, and isolating the body portion and each of the one and the other inlet-side water chambers and the one and the other outlet-side water chambers; The one inlet side water chamber is connected to one outlet side water chamber via one cooling pipe group, and the other inlet side water chamber is connected to the other outlet side water chamber and the other cooling pipe group. Among the condenser cooling pipes connected via the steam turbine, A cooling pipe in which seawater is leaking while the seawater level is determined from one inlet side and one outlet side water chamber, or from the other inlet side and other outlet side water chamber. A seawater discharge / salting process for detecting the salt concentration in the condensate retention part below the body part for each water level when discharging seawater, In the process, when the water level of the seawater is lowered by one step, and when the rate of change in the time gradient of the salinity concentration in the condensate retention portion becomes negative at the new water level after the water level is lowered by one step, A film sticking process for sticking a wrap film to all the pipe openings arranged in the water level change region for one stage on the pipe plate, and cooling when the shape of the wrap film in the pipe mouth changes to a predetermined state. The pipe is a leaking pipe E Bei the leakage determination process, the determining and that, in seawater discharge-Kenshio step, the water level is set to the horizontal arrangement rows of tubes orifice group are disposed in the tube plate, the seawater discharge-Kenshio step, at least 10 minutes when the reduced one step the water level is to characterized that you maintain its water level.
In the invention having the above-described configuration, the seawater drainage / salting step includes one inlet side and a seam draining / salting step in order to make it possible to attach a wrap film to a group of the cooling pipes arranged in the tube plate in the next step. Seawater is extracted from one outlet-side water chamber, or from the other inlet-side and other outlet-side water chambers, and the seawater is extracted step by step, and condensate stays every time the water level is lowered by one step. By observing the rate of change of the time gradient of the salinity concentration in the section, not all the mouths arranged in the tube plate, but the mouth port group consisting of a smaller number of mouths extracted from all the mouths It has the effect | action of extracting as a wrap film sticking object.
The film affixing process following this process is a process for affixing the wrap film only to the group of pipes extracted in the previous seawater drainage / salting process. Compared to the case of sticking, it has the effect of reducing the burden on the worker.
And in the last leak determination process, it has an effect | action which specifies what the sticking shape of the wrap film changed from the pipe opening group to which the wrap film was stuck as a leak cooling pipe.
Furthermore, in the invention according to claim 1, by setting the water level when the seawater is lowered stepwise in the seawater discharge / salting process as a lap film pasting target by setting between the horizontally arranged rows of the tube group on the tube plate This has the effect of increasing the accuracy of the determination as to whether or not the extracted cooling port includes the leakage cooling tube port.
In addition, in the first aspect of the invention, when the water level is lowered by one step, maintaining the water level for at least 10 minutes has the effect of increasing the detection accuracy of the rate of change in the salinity concentration time gradient.
Thereby, by the method described in claim 1, the effect of reducing the risk of making a determination error when extracting the port group for attaching the wrap film from all the tube ports arranged in the tube sheet. Have

The condenser cooling pipe specifying method for a condenser according to claim 2 is the condenser cooling pipe specifying method for a condenser according to claim 1 , wherein the water level is a tube plate in the seawater discharge / salting process. It is set for each horizontal arrangement row of the tube port group arranged in (1).
Present aspect, by addition to the same effect as the first aspect of the invention, to set the water level in lowering seawater stepwise in seawater discharge-Kenshio process every horizontal arrangement rows, wrap film Has the effect that the maximum number of pipe ports for attaching the number is the number of all the pipe openings constituting one horizontal arrangement row.
That is, it has the effect of making it possible to determine in which horizontally arranged row of all the tube port groups the tube port of the leakage cooling tube is located.

According to the condenser cooling pipe specifying method for a condenser according to claim 1 of the present invention, as in the prior art (as in the case of the invention disclosed in Patent Document 1), There is no need to attach a wrap film to the tube opening. That is, since it is only necessary to attach the wrap film to only a part of the pipe ports including the pipe port of the leakage cooling pipe, it is possible to improve the work efficiency of the specific operation of the leakage cooling pipe in the condenser.
In addition, the operation of extracting the port group for attaching the wrap film from all the tube ports can be performed from one inlet side and one outlet side water chamber of the condenser, or from the other inlet side and the other outlet side water chamber. It can be performed in conjunction with the work of discharging the cooling water.
Further, since the salt detection means used in the seawater discharge / salting process is permanently installed in the condenser, a new facility is newly provided to carry out the condenser leak cooling pipe identification method according to claim 1. There is no need to add.
Therefore, according to invention of Claim 1, the work efficiency of the specific operation | work of the leaking cooling pipe of a condenser can be improved, without performing capital investment at all.
Furthermore, according to the first aspect of the present invention, in the seawater discharge / salting process, the pipe port of the leakage cooling pipe is included in the pipe port arranged in the water level change region for one stage on the tube plate. When determining whether or not, the accuracy of the determination can be increased. Thereby, while improving the work efficiency of the specific operation | work of the leakage cooling pipe of a condenser, the precision can also be raised.
In addition, according to the first aspect of the present invention, it is possible to reduce the risk of erroneous reading of the rate of change in the time gradient of the salinity concentration in the seawater discharge / salting process. As a result, it is possible to accurately extract the tube port group that needs to be attached with the wrap film.

In addition to the same effect as that of the invention of the first aspect , the invention according to the second aspect has one horizontal arrangement line in all the pipe openings arranged on the tube plate with a minimum number of pipe openings for attaching the wrap film. Can be in minutes.
In the prior art, when identifying a ductal orifice leakage condenser, it was necessary Keru sticking a wrap film for all ductal orifice that is disposed in the tube plate, according to the second aspect of the invention, minimum In this case, the leakage cooling pipe can be accurately identified only by sticking the wrap film to the pipe openings for one horizontally arranged line among the pipe openings arranged in the tube plate.
Therefore, the work efficiency of the specific work of the leakage cooling pipe can be greatly improved as compared with the prior art.

It is a cross-sectional perspective view of the condenser used for this Embodiment. It is sectional drawing of the condenser used for this Embodiment. It is an arrow view for demonstrating the change of the water level in the inlet side water chamber in the condenser which concerns on Example 1 of this invention, or an outlet side water chamber. It is a flowchart which shows the process of the leak cooling pipe identification method of the condenser which concerns on Example 1 of this invention. It is an arrow line view for demonstrating the example of the change of the water level in the inlet side water chamber or the outlet side water chamber in the condenser which concerns on Example 2 of this invention.

A condenser cooling pipe specifying method for a condenser according to an embodiment of the present invention will be described in detail with reference to Example 1 and Example 2.
The condenser cooling pipe specifying method according to the present invention is a use invention of the invention disclosed in Patent Document 1 described above, and the general configuration of the thermal power plant is disclosed in Patent Document 1. Therefore, detailed description thereof will be omitted.

First, a condenser which is an object of implementation of the method for specifying a condenser condenser leak leakage pipe according to the present invention will be described in detail with reference to FIGS.
FIG. 1 is a cross-sectional perspective view of a condenser used in the present embodiment with a part thereof omitted. 2 is a cross-sectional view taken along line PP in FIG. FIG. 2 shows a state where both the inlet and outlet water chambers are filled with seawater W as cooling water.
As shown in FIGS. 1 and 2, the condenser 2 according to the present embodiment mainly includes a body portion 3 and first and second inlet side water chambers 4 </ b> A provided on one side of the body portion 3. 4B, and first and second outlet-side water chambers 5A and 5B provided on the other side of the body portion 3. The first inlet-side water chamber 4A, the first outlet-side water chamber 5A, and the second The inlet-side water chamber 4B and the second outlet-side water chamber 5B are connected to each other by a plurality of cooling pipes 6, and the seawater W as cooling water is supplied from the first and second inlet-side water chambers 4A and 4B. It is configured to flow into the first and second outlet-side water chambers 5A and 5B via the cooling pipe 6, and when the seawater W passes through the trunk part 3 by the cooling pipe 6, the steam supply part 20 to the trunk part 3 The used steam is cooled and aggregated in the power generation turbine that is fed to the turbine.

More specifically, in the condenser 2 according to the present embodiment, the first inlet-side water chamber 4A and the second inlet-side water chamber 4B are provided on the inlet side to which the seawater W used as cooling water is supplied. A first outlet-side water chamber 5A and a second outlet-side water chamber 5B are provided on the outlet side where the seawater W is discharged, and the first inlet-side water chamber 4A and the first outlet-side water chamber are provided. A plurality of cooling pipes 6 connecting 5A are arranged in parallel in the body portion 3 to form a first cooling pipe group 7A, and a cooling pipe connecting the second inlet side water chamber 4B and the first inlet side water chamber 4A. 6 are arranged in parallel in the body part 3 to form a second cooling pipe group 7B, and the body part 3 forms a tube nest 8 composed of the first and second cooling pipe groups 7A and 7B.
The first and second inlet-side water chambers 4A and 4B and the body portion 3 and the first and second outlet-side water chambers 5A and 5B and the body portion 3 are both partitioned by a tube plate 9. The tube plate 9 supports one end 6 a and the other end 6 b of the cooling tube 6, and the cooling tube 6 is disposed in parallel in the body portion 3. Then, the tube ports 10 of the cooling pipe 6 are regularly arranged in the first and second inlet-side water chambers 4A and 4B and the tube plates 9 of the first and second inlet-side water chambers 4A and 4B. Yes.

A cooling water supply pipe 12 having a cooling water supply valve 11 is connected to each of the first and second inlet-side water chambers 4A and 4B, and the first and first water chambers 4A and 4B are connected via the cooling water supply pipe 12. Seawater W is supplied to each of the two inlet-side water chambers 4A and 4B.
A cooling water drain pipe 14 having a cooling water drain valve 13 is connected to each of the first and second outlet-side water chambers 5A and 5B, and the first and second outlets are connected via the cooling pipe 6. The seawater W flowing into the first and second outlet-side water chambers 5A, 5B from the inlet-side water chambers 4A, 4B is discharged out of the condenser 2 through the cooling water drain pipe 14. ing.

Further, a condensate retention portion 15 for storing condensate 17 formed by cooling and condensing water vapor in the tube nest 8 of the trunk portion 3 is provided at the lower portion of the condenser 2. Furthermore, a condenser outlet 16 is provided at the bottom 15a of the condensate retention part 15, and the condensate 17 condensed in the condenser 2 is heated again and fed to the turbine to pass through the power plant. Circulate.
The condensate retention part 15 is partitioned by a partition plate 18, and is cooled and aggregated by the first cooling pipe group 7A and condensed by being cooled by the second cooling pipe group 7B. Thus, the condensate 17 is not mixed with each other.
Further, the first staying portion 15A on the first cooling tube group 7A side and the second staying portion 7B on the second cooling tube group 7B side (not shown, but to distinguish from the first staying portion 15A) Each bottom portion 15a (which is provided with a reference for convenience) is provided with a salinometer 19 and can detect leakage of seawater W from the cooling pipe 6 by monitoring the salinity concentration in the condensate 17. It is configured.
That is, since the condensate retention part 15 is partitioned by the partition plate 18, when an abnormality in the salinity concentration is detected in the first retention part 15A, a leakage pipe exists in the first cooling pipe group 7A. On the other hand, if an abnormality in the salinity concentration is detected in the second staying portion 15B, a leakage pipe exists in the second cooling pipe group 7B.
Here, the case where there is a leakage pipe in the first cooling pipe group 7A and the position thereof is specified will be described as an example.

Although not particularly shown in FIGS. 1 and 2, a part of the condensate 17 collected in the condensate retention part 15 (15A, 15B) is extracted from the condensate retention part 15 (15A, 15B). After being desalted in a condensate desalination apparatus (not shown), it is returned again to the condensate retention part 15 (15A, 15B).
More specifically, a part of the condensate 17 is extracted from the condensate retention part 15 (15A, 15B) by a condensate pump (not shown) and sent to a condensate demineralizer, where desalination is performed. After the processing, it is supplied to the turbine through a low pressure heater, a deaerator, a feed water pump, a high pressure heater, and a boiler (not shown), and is returned to the condenser 2 again through the steam supply unit 20.
Therefore, depending on the amount of condensate 17 extracted from the condensate retention part 15 (15A, 15B) for feeding to the condensate demineralizer, if the first cooling pipe group 7A has a leakage pipe, Even if the condensate demineralizer is operating, seawater continues to be supplied to the condensate retention part 15A at a constant speed. For this reason, the salinity concentration in the condensate 17 detected by the salinometer 19 of the condensate retention part 15A is constant as long as the supply amount of seawater does not decrease the treatment capacity of the desalting apparatus over a considerable time. It will change by value.
That is, when specifying the position of the leak pipe inlet 10 in the first cooling pipe group 7A of the condenser 2, even if the condensate demineralizer is still operating at a certain processing capacity, As long as the seawater is filled to the level and the seawater supplied from the leak pipe continues to flow into the condensate retention part 15A in a certain amount, the salinity concentration of the condensate 17 in the condensate retention part 15A changes at a constant value. Will do.
However, when seawater leaks from the leak pipe, the salinity is not supplied, so that the increase rate of the salinity concentration decreases, the increase in the salinity concentration stops, or the salinity concentration decreases. In other words, the rate of change in the salinity concentration time gradient is negative.

A condenser cooling pipe specifying method for a condenser according to Embodiment 1 of the present invention will be described in detail with reference to FIGS.
FIG. 3 is an arrow view for explaining a change in the water level in the inlet-side water chamber or the outlet-side water chamber in the condenser according to the first embodiment of the present invention. That is, FIG. 3 is an arrow view seen from the direction indicated by the symbol Q in FIG. In addition, the same code | symbol is attached | subjected about the same part as what was described in FIG. 1 or FIG. 2, and the description about the structure is abbreviate | omitted.
As shown in FIGS. 1 to 3, in the condenser 2, the trunk portion 3 and the first inlet-side water chamber 4 </ b> A, the second inlet-side water chamber 4 </ b> B, and the trunk portion 3 and the first outlet-side water chamber. It is assumed that the tube ports 10 are arranged in a total of 30 locations, for example, 6 rows in the horizontal direction and 5 columns in the vertical direction, in each tube plate 9 that partitions the 5A and second outlet-side water chambers 5B. The rows arranged in the horizontal direction in the port group 10 are referred to as A row, B row, C row,.

First, the principle by which a horizontally arranged pipe opening line including a leakage cooling pipe is extracted by the condenser cooling pipe specifying method of the condenser according to the first embodiment will be described.
As shown in FIG. 2, when all the pipe ports 10 arranged in the tube plate 9 in the first inlet side water chamber 4A and the first outlet side water chamber 5A are filled with seawater W so as to be submerged. That is, when the seawater W is filled up to the position indicated by the symbol i in FIG. 3 and when the salt concentration meter 19 detects an abnormality (increase) in the concentration of salinity in the condensate, The tube port 10 belonging to any one of the horizontally arranged rows includes the tube port 10 of the leak tube.
Next, in the case where the water level of the seawater W is lowered by one step to the position indicated by the symbol ii in FIG. 3 between the A row and the B row in the port group shown in FIG. If the change rate of the time gradient of the salinity concentration detected in 19 is not negative, the change in the change rate of the time gradient of the salinity concentration occurs because the salinity is supplied from the seawater without the port 10 belonging to the A row. Therefore, it can be determined that the row A does not include the pipe port 10 of the leak pipe. In this case, it can be determined that the tube port 10 of the leak tube is included in the tube ports 10 belonging to the remaining horizontally arranged rows B to F.
On the other hand, when the rate of change in the time gradient of the salinity concentration detected by the salinometer 19 becomes negative when the seawater W is lowered to the position indicated by symbol ii in FIG. It can be determined that the tube port 10 of the leak tube exists in the tube port group 10. This is because the supply of salt stops because the seawater from the group of pipe ports 10 belonging to the A row no longer leaks, and the rate of change in the time gradient of the salt concentration becomes negative. Moreover, since it cannot be said that the pipe port 10 which belongs to the horizontal arrangement | positioning row | line of the remaining BF rows does not contain the pipe port 10 of another leaking pipe, it continues and the water level of each step falls. It is necessary to observe the rate of change of the time gradient of the salinity concentration by the salinometer 19 in FIG.
In the specification and claims of the present application, “one stage” means that between the tube ports belonging to a certain horizontal arrangement row and between the tube ports belonging to the adjacent horizontal arrangement row in the tube group. It means a unit of movement. For example, the case where the water level which existed between A line and B line is moved between B line and C line corresponds. The change rate of the salinity concentration time gradient is the acceleration of the salinity concentration, that is, the change rate of the salinity concentration time gradient. Therefore, not only when the supplied salt content is stopped, but also when a leak pipe is included in the row of the plurality of port openings 10, the amount of salt supplied through the row including the first leak pipe is reduced. However, even in the case where it does not stop completely, the time gradient of the salinity becomes slow and the rate of change becomes negative.

Subsequently, in the case where the water level of the seawater W is lowered to the position indicated by the symbol iii in FIG. 3 between the B row and the C row in the port group shown in FIG. When the change rate of the time gradient of the salinity concentration detected in the total 19 does not become negative, it can be determined that the pipe port 10 belonging to the B row does not include the pipe port 10 of the leak pipe.
On the other hand, when the seawater W is lowered by one step to the position indicated by the symbol iii in FIG. 3 and the rate of change of the time gradient of the salinity concentration detected by the salt analyzer 19 is negative, It can be determined that the pipe port 10 of the leak pipe exists in the group of pipe ports 10 belonging to the above. Further, since it cannot be said that the tube ports 10 belonging to the remaining horizontally arranged rows C to F do not include the tube port 10 of the leak tube, the water level is continuously lowered and the detection at each water level is continued. It is necessary to observe the rate of change of the salinity concentration time gradient by the salt meter 19.

Further, in the case where the water level of the seawater W is lowered by one step between the C row and the D row, that is, the position indicated by the symbol iv in FIG. If the rate of change of the time gradient of the salinity concentration detected in step S does not become negative, it can be determined that the port 10 of the leaking tube is not included in the port 10 belonging to the C row.
On the other hand, when the seawater W is lowered to the position indicated by the symbol iii in FIG. 3 and the rate of change in the time gradient of the salinity concentration detected by the salt analyzer 19 becomes negative, it belongs to the C row. It can be determined that the tube port 10 of the leak tube exists in the tube port group 10. Moreover, since it cannot be said that the pipe ports 10 belonging to the remaining horizontal rows D to F do not include the pipe port 10 of the leak pipe, the water level is gradually lowered and the detection at each water level is continued. It is necessary to observe the rate of change of the salinity concentration time gradient by the salt meter 19.

Thus, when the water level of the seawater W is lowered by one step, the rate of change in the time gradient of the salinity concentration detected by the salt analyzer 19 provided in the first retention part 15A is negative. After that, the rate of increase in the salt concentration in the condensate 17 in the first staying portion 15A decreases, or the change in the salt concentration stops or the salt concentration decreases. It means that
That is, the phenomenon that the rate of increase of the salinity concentration in the condensate 17 in the first staying part 15A, or the change of the salinity concentration is stopped or the salinity concentration is decreased is the first phenomenon with the change of the water level of the seawater W. This supports the fact that the amount of leakage of seawater W from the cooling tube group 7A has decreased.
That is, it can be said that at least one of the leak pipes 10 is included in the pipe 10 arranged in the change region of the water level of the seawater W for one stage.

On the other hand, when the water level of the seawater W is lowered by one step, if the rate of change in the time gradient of the salinity concentration detected by the salt analyzer 19 provided in the first staying portion 15A does not become negative, This means that there is no change in the speed of increase (rise) of the salt concentration in the condensate 17 in the first staying portion 15A before and after the water level is lowered by one step.
That is, even if the water level of the seawater W is changed, the reason why the speed of increase (increase) of the salinity concentration in the condensate 17 in the first staying portion 15A does not change is the seawater W from the first cooling pipe group 7A. This is none other than that no leakage has occurred.
That is, it means that the pipe port 10 of the leak pipe does not exist in the pipe port 10 arranged in the water level change region of the seawater W for one stage.

Here, the flow of the condenser cooling pipe specifying method of the condenser according to the first embodiment will be described in detail with reference to FIG.
FIG. 4 is a flowchart illustrating the steps of the condenser cooling pipe specifying method for a condenser according to the first embodiment of the present invention. The same parts as those described in FIGS. 1 to 3 are denoted by the same reference numerals, and description of the configuration is omitted.
First, the state during normal operation, that is, a state where no leakage has occurred in the cooling pipes 6 constituting the first cooling pipe group 7A will be described with reference to FIG.
During normal operation, the salt concentration in the condensate 17 is detected by the salt meter 19 at the condensate retention part 15 (first retention part 15A) of the condenser 2 at all times or at regular intervals (step S0). ) If no abnormal salinity in condensate 17 is detected (an increase in salinity), step S0 is repeated.

On the other hand, when an increase in the salinity concentration in the condensate 17 is detected in the previous step S0, it is determined that leakage has occurred in the cooling pipes 6 constituting the first cooling pipe group 7A. According to the condenser cooling pipe specifying method 1 related to the above, the leak pipe is specified.
In the condenser cooling pipe specifying method 1 according to the first embodiment, first, the salinity concentration in the condensate 17 in a state where the first inlet water chamber 4A and the first outlet water chamber 5A are full. Is detected (step S1), and when the rate of change in the time gradient of the salinity concentration becomes negative in step S1, the determination in the previous step S0 is an erroneous determination and the process returns to step S0 again.

On the other hand, if an abnormality is detected again in the salinity concentration in the condensate 17 in this step S1, that is, if the rate of change in the time gradient of the salinity concentration does not become negative, the horizontal arrangement line including the pipe port 10 of the leakage pipe The following steps are carried out to identify the group of pipe ports 10.
First, in the first inlet-side water chamber 4A and the first outlet-side water chamber 5A, the water level is lowered by one stage from the full state (step S2), and the state is maintained for a certain period of time and measured by the salt analyzer 19 It is observed whether or not the rate of change of the time gradient of the salinity concentration of the condensate 17 is negative (step S3).
In the case where the water level of the seawater W is lowered by one step in step 2, the lowered water level may be set to the horizontal arrangement line 21 in the port group 10 as shown in FIG. In this case, since the tube port 10 provided in the tube plate 9 can be made into only two types of the state completely submerged in the seawater W and the state completely exposed from the seawater W, It is possible to accurately determine whether or not the tube port 10 of the leak tube is included in the tube port 10 group constituting each horizontal arrangement row.

This is clear from the example shown below. For example, if the water level is set so that only a part of the pipe port 10 is submerged in the seawater W, the cooling pipe 6 connected to the pipe port 10 is not filled with the seawater W, so that there is a leakage location in the cooling pipe 6. In some cases, leakage of seawater W from the cooling pipe 6 does not occur. In this case, the rate of change in the time gradient of the salinity concentration in the condensate 17 does not change, and the horizontal arrangement row is configured. It becomes impossible to accurately determine whether or not the tube port group 10 includes the tube port 10 of the leak tube.
Therefore, when the water level of the seawater W is lowered by one step in step 2, it is desirable to set the lowered water level in the horizontally arranged row 21 of the port group 10 as shown in FIG.
Moreover, when implementing step S3 shown in FIG. 4, it is desirable to maintain the water level lowered in the previous step S2 for at least 10 minutes. This is because if the maintenance time of the water level after lowering the water level is within 10 minutes, the change in the rate of change in the time gradient of the salinity concentration in the condensate 17 is not accurately reflected, and an erroneous determination may occur. There is not preferable.

  When the rate of change in the time gradient of the salinity concentration in the condensate 17 does not become negative in step 3, the group of the tube ports 10 arranged in the water level change region for one step on the tube plate 9, In other words, in the first embodiment, it can be determined that the tube port 10 of the leak tube is not included in the tube port group 10 constituting one horizontally arranged row.

  On the other hand, when the rate of change in the time gradient of the salinity concentration in the condensate 17 becomes negative in step S3 after performing step S2, the water level for one stage on the tube plate 9 in step S2 immediately before that It can be determined that the port 10 of the leaking pipe is included in the group 10 of the ports arranged in the change region (the group of ports 10 constituting one horizontally arranged row in the first embodiment). .

As described above, in the condenser cooling pipe specifying method 1 according to the first embodiment, the above-described step S2 and step S3 are repeated, that is, the tube sheet for all the first cooling pipe groups 7A. By observing the rate of change of the time gradient of the salinity concentration in the condensate 17 before the water level of the seawater W on 9 is lowered and after the water level is lowered by one step, the wrap film is removed in the next step S4. It is possible to extract the tube group 10 to be pasted.
Then, as described above, the water level of the seawater W is set to the highest level of the group of pipe ports 10 arranged in the tube plate 9 one step at a time from the full state of the tube plate 9 (one horizontal arrangement row in the first embodiment). Lower to the lower stage (to the position indicated by reference sign vii in FIG. 4) (step S2), and observe the rate of change in the time gradient of the salinity concentration in the condensate 17 each time (step S3), one step The step of determining whether or not the pipe port 10 of the leak pipe is included in the group of pipe ports 10 arranged in the water level changing region is the seawater drainage / salting process 23.
Then, in the subsequent step S4, a wrap film is pasted on all the port ports 10 constituting all the tube port groups considered to include the tube ports 10 of the leaking tubes, and after this step S4, the lap film is pasted on the tube port 10. When it is confirmed that the wrap film is deformed into a predetermined shape, the cooling pipe 6 connected to the pipe port 10 can be identified as a leak pipe (step S5).
More specifically, for example, the wrap film attached to the tube opening 10 is pulled into the cooling tube 6 to change into a concave shape, or the wrap film attached to the tube opening 10 is broken. When this occurs, it can be determined that the cooling pipe 6 is a leakage pipe.

In the case of the method for identifying a condenser cooling pipe (disclosed in Patent Document 1) according to the prior art, the first inlet-side water chamber 4A is used to identify the leakage pipe from the first cooling pipe group 7A. Moreover, it is necessary to attach a wrap film to all the tube ports 10 arranged in the respective tube plates 9 of the first outlet-side water chamber 5A, which is complicated.
On the other hand, according to the condenser cooling pipe specifying method 1 according to the first embodiment, the seawater W as cooling water is extracted from the first inlet-side water chamber 4A and the first outlet-side water chamber 5A. Perform the work step by step, and measure the salinity concentration in the condensate 17 by the salinometer 19 installed in the condensate retention part 15 (first retention part 15A) every time the water level of the seawater W is lowered by one stage. Paste the wrap film by observing the change rate of the time gradient of the salinity concentration measured before the water level is lowered by one step and the change rate of the time gradient of the salinity concentration after the water level is lowered. The number of the outlets 10 can be limited and the number thereof can be greatly reduced.
In particular, in the case of the condenser cooling pipe specifying method 1 according to the first embodiment, since the change in the water level of the seawater W on the tube plate 9 is set to the group of tube ports 10 for one horizontal arrangement row, a wrap film is pasted. The number of pipe ports 10 can be a multiple of one horizontally arranged row.
According to the condenser cooling pipe specifying method 1 according to the first embodiment, it is possible to specify the position of the outlet of the leak pipe with a small amount of work without reducing accuracy. Therefore. The work efficiency of the specific work of the leak pipe can be improved.
Further, according to the condenser cooling pipe specifying method 1 according to the first embodiment, since the pipe port 10 of the leaking pipe can be specified while the turbine is operating in the power plant, the replacement of the leaking pipe, etc. The time for stopping the turbine in maintenance can be shortened.

Although not particularly illustrated, the water levels of the first inlet-side water chamber 4A, the first outlet-side water chamber 5A, the second inlet-side water chamber 4B, and the second outlet-side water chamber 5B are A water level meter or water level sensor is provided for enabling monitoring from outside the condenser 2.
This water level gauge is individually and independently for each of the first inlet-side water chamber 4A, the first outlet-side water chamber 5A, the second inlet-side water chamber 4B, and the second outlet-side water chamber 5B. One water level meter or water level sensor may be provided for the first inlet-side water chamber 4A and the first outlet-side water chamber 5A, and the second inlet-side water chamber 4B and the second outlet may be provided. Another water level meter or water level sensor may be provided separately for the side water chamber 5B.
In this case, the water level of the seawater W is stepped from the first inlet-side water chamber 4A, the first outlet-side water chamber 5A, the second inlet-side water chamber 4B, and the second outlet-side water chamber 5B of the condenser 2. Therefore, the operation can be performed smoothly and accurately.
Also, when implementing the condenser cooling pipe specifying method according to Example 2 below, it is desirable to use the condenser 2 provided with a water level meter or a water level sensor as described above.
In addition, the concept of providing a water level meter and a water level sensor in the specification of the present application includes a case where the water level gauge and the water level sensor are provided in advance, and the case where they are provided only during inspection.

A condenser cooling pipe specifying method for a condenser according to the second embodiment will be described in detail with reference to FIG.
FIG. 5 is an arrow view for explaining an example of a change in the water level in the inlet-side water chamber or the outlet-side water chamber in the condenser according to the second embodiment of the present invention. That is, FIG. 5 is also an arrow view seen from the direction indicated by the symbol Q in FIG.
In the condenser cooling pipe specifying method 1 according to the first embodiment, the seawater W of the first inlet-side water chamber 4A and the first outlet-side water chamber 5A is disposed on the tube plate 9. Although the case where the level is lowered step by step in the group of mouths 10 has been described as an example, the amount of change in the water level of the seawater W does not necessarily have to be one row arranged horizontally.
In addition, when the number of horizontally arranged rows of the tube ports 10 arranged in the tube plate 9 is large, when the condenser cooling pipe specifying method 1 of the condenser according to the first embodiment is performed, the water level is lowered step by step. The amount of displacement of the water level is one horizontal arrangement line, and it is desirable to maintain the water level for at least 10 minutes every time the one-stage water level is lowered. It may be considered that a lot of time is required to discharge the seawater W from 4A and the first outlet-side water chamber 5A, and the work efficiency is lowered.

In view of such circumstances, the condenser cooling pipe specifying method according to the second embodiment is the same as the condenser cooling pipe specifying method 1 according to the first embodiment shown in FIG. The amount of displacement of the water level to be lowered in step S2 is set larger than in the case of the first embodiment.
For example, as shown by reference numerals I, II, III, and IV in FIG. 5, when the amount of displacement of the water level is set for every two horizontally arranged rows, the number of the pipe ports 10 to which the wrap film is pasted is the example. The time required to discharge the seawater W from the first inlet-side water chamber 4A and the second inlet-side water chamber 4B is about half that in the case of the first embodiment, although it is twice that of the first case. .

  The condenser cooling pipe specifying method according to the second embodiment is the same as the condenser cooling pipe specifying method 1 according to the first embodiment except that the amount of displacement of the water level in step S2 is different. Therefore, it has the same effect as the leakage cooling pipe specifying method 1 of the condenser according to the first embodiment.

  As described above, the present invention provides a cooling pipe in which seawater is leaked in a condenser without suspending the turbine by observing a change in the surface of the cooling pipe by wrapping a wrap film. In the condenser cooling pipe identification method for identifying the condenser, the leakage of the condenser pipe can be reliably identified by simply attaching a wrap film to only a part of the pipe group including the outlet of the leakage pipe. The present invention relates to a cooling pipe specifying method and can be used in the field of equipment such as a thermal power plant and a nuclear power plant.

  DESCRIPTION OF SYMBOLS 1 ... Condenser leak cooling pipe identification method 2 ... Condenser 3 ... Body part 4A ... 1st inlet side water chamber 4B ... 2nd inlet side water chamber 5A ... 1st outlet side water chamber 5B ... 1st 2 outlet side water chamber 6 ... cooling pipe 6a ... one end 6b ... the other end 7A ... first cooling pipe group 7B ... second cooling pipe group 8 ... tube nest 9 ... tube plate 10 ... pipe port 11 ... cooling water supply valve 12 ... Cooling water supply pipe 13 ... Cooling water discharge valve 14 ... Cooling water discharge pipe 15 ... Condensate staying part 15A ... First staying part 15B ... Second staying part (not shown) 15a ... Bottom part 16 ... Condenser Exit 17 ... Condensate 18 ... Partition plate 19 ... Salt meter 20 ... Steam supply part 21 ... Horizontally arranged line 22 ... During normal operation W ... Seawater 23 ... Seawater drainage / salt test process

Claims (2)

Sea water used as cooling water to condense the steam discharged from the steam turbine is passed, one and the other cooling pipe group consisting of a plurality of cooling pipes, a body part in which the cooling pipe group is arranged, and the cooling One and other inlet-side water chambers for supplying the seawater to the pipe, one and other outlet-side water chambers for receiving the seawater that has passed through the cooling pipe, and fixing both ends of the cooling pipe; A pair of tube plates that isolate the one and the other inlet side water chambers and the one and the other outlet side water chambers,
The one inlet-side water chamber is connected to the one outlet-side water chamber via the one cooling pipe group, and the other inlet-side water chamber is connected to the other outlet-side water chamber and the other cooling chamber. Among the cooling pipes of a condenser connected via a tube group, a method of identifying a cooling pipe in which the seawater leaks while the steam turbine is operating,
The seawater is discharged from the one inlet side and one outlet side water chamber or the other inlet side and other outlet side water chamber while the water level of the seawater is lowered stepwise, A seawater discharge / salting step for detecting the salinity concentration in the water retention portion for each of the water levels when discharging the seawater;
In the seawater discharge / salting step, when the water level of the seawater is lowered by one step, and at the new water level after the water level is lowered by one step, When the rate of change of the time gradient is negative, a film sticking step of sticking a wrap film to all the tube ports arranged in the water level change region for one stage on the tube plate;
E Bei and a leakage determination step of the shape of the wrap film of the tube opening determines that the cooling pipes when changing to a predetermined state is leaking tube,
In the seawater discharge / salting step, the water level is set between horizontally arranged rows of tube groups arranged in the tube sheet,
In the seawater discharge-Kenshio step, at least 10 minutes leaky condenser particular method condenser characterized that you maintain its water level the water level when the reduced one step. In the seawater discharge-Kenshio step, the water level, leakage cooling condenser according to claim 1, wherein the set for each 1 horizontal arrangement row of tubes orifice group are disposed in the tube plate Tube identification method.