JP5463727B2 - Condenser cooling pipe leak inspection device - Google Patents

Description

  The present invention relates to a condenser for cooling steam discharged from a steam turbine to recover water, and in particular, a condenser for inspecting leakage (leakage) of a condenser cooling pipe (heat transfer pipe). The present invention relates to a cooling pipe leakage inspection device.

  Conventionally, steam generated by a boiler in a power plant or the like is used as power for turning a turbine, and then sent to a condenser to be liquefied and cooled, and is again heated by a boiler as water to become steam. A structure that circulates like this is taken. In this case, the water vapor side of the condenser is operated in a vacuum state of about −700 mmHg. This is because when the water vapor (gas) becomes water (liquid), the volume decrease becomes negative pressure, so the heat drop is reduced. Increasing the efficiency increases efficiency.

  FIG. 5 shows a general configuration of a condenser of a steam turbine (see Patent Document 1), FIG. 5 (a) is a side view, and FIG. 5 (b) is an XX arrow view. . 5 (a) and 5 (b), reference numeral 70 denotes a condenser main body, and a steam turbine 71 is disposed in the upper part. Reference numeral 72 denotes a body. Tube bodies 73 are provided on both sides of the body 72, and both tube plates 73 support a cooling tube group 74 including a plurality of cooling tubes. Usually, as shown in FIG. 5B, the cooling tube group 74 is divided into two chambers, a chamber A and a chamber B, and the number of cooling tubes in each chamber reaches several thousand to several tens of thousands. Incidentally, if necessary, one of the A room and the B room is stopped and the operation (one lung operation) can be performed only on one side.

  75a and 75b are water chambers. Cooling water 80a flows in from the water chamber 75a, flows in the cooling pipes of the cooling pipe group 74, and flows out from the water chamber 75b as cooling water 80b. 76 is a condensate reservoir, in which water vapor is cooled and condensed by the cooling water flowing in the cooling pipe, and is accumulated in the lower part. Reference numeral 77 denotes a condensate outlet, which is an outlet for water accumulated in the condensate reservoir 76.

  The water chambers 75a and 75b are provided in the A chamber and the B chamber, respectively. Although not shown, each of the water chambers 75a and 75b is provided with a manhole, and at the time of inspection or repair, the cooling water is extracted from the A room or / and the B room, and the A room or / And a worker can enter the water chambers 75a and 75b of the B room.

  In the condenser having the above-described configuration, the water vapor 81 which has been expanded by the steam turbine 71 and has worked to become a low temperature flows into the condenser main body 70 and flows into the cooling pipe group 74 in the body 72. The water vapor that has flowed into the cooling pipe group 74 is cooled by the cooling water in the process of flowing between a large number of cooling pipes through which the cooling water flows, condenses on the surface of the cooling pipe, becomes water, and falls into the condensate reservoir 76 below. . The water accumulated in the condensate reservoir 76 flows out of the condensate outlet 77 and is returned to the heating source again.

  At that time, in general, large power plants are often established on the coast, and seawater is often used as the cooling water.

  In the case of such a condenser that uses seawater as cooling water, if a hole is opened in the cooling pipe for some reason (for example, corrosion by seawater) and cooling water (seawater) leaks from it, it is used for boilers. Since seawater is mixed with pure water, the salinity of the condensate becomes high, which may cause fatal damage to the boiler body. Therefore, it is necessary to detect the leakage of the cooling pipe at an early stage and close the leakage pipe.

  At that time, it is very difficult to directly detect the leakage (leakage) of the cooling pipe by visual inspection of the worker. Conventionally, the leakage of the cooling pipe is detected using a thin vinyl sheet or soapy water (foam). It was.

  However, inspecting the leakage of a large number of cooling pipes reaching several thousand to several tens of thousands is a time-consuming and persevering work, often relying on intuition and experience, and lacking certainty.

  On the other hand, several condenser cooling pipe leakage inspection techniques have been proposed so far, which aim to accurately leak condenser condenser pipes in a short time.

  For example, Patent Document 1 discloses an inner cap that seals the inside of the cooling pipe by sealing the inside of the cooling pipe with both ends opened and closed against the pipe plates around both openings of the cooling pipe supported by the pipe plate. An outer cap that covers and seals the outer periphery of the cap; a pressurizing means that pressurizes the space formed by the outer cap and the inner cap and the inside of the cooling pipe sealed by the inner cap to an equal pressure; and A pressure holding means for holding a constant pressure in a space formed by the outer cap and the inner cap; and a space formed by the cooling pipe sealed by the inner cap, and the outer cap and the inner cap. A condenser condenser leak detection device having a differential pressure gauge for measuring differential pressure is described.

  In Patent Document 2, a plug with a pressure sensor is inserted into one end of a cooling pipe, and a plug is inserted into the other end to close both ends, and leakage due to a pressure difference between the inside of the cooling pipe and the steam side outside the cooling pipe. A condenser condenser leak detection technique is described that detects leaks in the condenser by measuring pressure fluctuations due to outflow from the mouth.

  Patent Document 3 includes a means for sealing both ends of the condenser cooling pipe and a sensor attached to one end of the means for sealing the cooling pipe. A condenser condenser leak detector that detects the presence or absence of pinholes in the condenser pipe by detecting the differential pressure between the reduced pressure in the cooling caused by the air leaking into the condenser and the atmospheric pressure by the sensor. Is described.

  Also, in Patent Document 4, covers are installed at both ends of the condenser cooling pipe, the cooling pipe is evacuated with a vacuum pump, and a drop in water level is confirmed (visually) with a water level gauge attached to the cover. Describes a condenser condenser leak inspection system that detects leaks in condenser pipes.

Japanese Patent Laid-Open No. 2000-1446459 JP 2000-154986 A Japanese Patent Application Laid-Open No. 06-026978 Japanese Patent Laid-Open No. 62-09195

  However, the techniques described in Patent Documents 1 to 4 have the following problems.

  First, with respect to the technique described in Patent Document 1, the structure of caps installed at both ends of a water-cooled tube is complicated, and a long time is required from installation to detection.

  Moreover, about the technique of patent document 2, since the plug installed in the both ends of a water cooling pipe is a screwing type, installation requires a lot of time. Also, the leak detection system is complex and expensive.

  In addition, the techniques described in Patent Documents 3 and 4 are leakage detection devices that utilize the fact that the condenser (water vapor side) is in a vacuum state while the condenser is in operation. Cannot be used when the vessel is stopped. In addition, the leak detection system is complicated and expensive.

  This invention is made | formed in view of the above situations, and provides the condenser cooling pipe leak test | inspection apparatus which can test | inspect the presence or absence of the leakage of the condenser pipe of a condenser simply and efficiently. It is for the purpose.

  In order to solve the above problems, the present invention has the following features.

[1] Pressure fluctuation for measuring pressure fluctuation in the cooling pipe at one end of the cooling pipe in order to detect a cooling pipe having a hole in the condenser pipe group in the condenser and causing leakage of the cooling water. A pressure fluctuation measuring end plug communicating with the measuring means is inserted, a closed end plug for closing the cooling pipe is inserted into the other end of the cooling pipe, and a pressure difference between the cooling pipe and the outside of the cooling pipe is inserted from the hole. A condenser cooling pipe leakage inspection device that detects leakage of a cooling pipe by measuring the pressure fluctuation in the cooling pipe accompanying outflow by the pressure fluctuation measuring means,
A plurality of pressures corresponding to the arrangement of the cooling pipes so that the presence or absence of leakage can be inspected by one pressure fluctuation detecting means by simultaneously inserting the pressure fluctuation measuring end plug and the closed end plug into the plurality of cooling pipes. A pressure fluctuation measuring end plug group in which fluctuation measuring end plugs are gathered in a triangular shape and a closing end plug group in which a plurality of closing end plugs are gathered in a triangular shape, and the pressure in the pressure fluctuation measuring end plug group A condenser cooling pipe leakage inspection device characterized in that the variable end plugs communicate with each other.

  [2] When the arrangement of the cooling pipes is a staggered arrangement, the pressure fluctuation measuring end plug group including a total of six pressure fluctuation measuring end plugs including one, two, and three, and a total of six closed end plugs. A closed end plug group, or a pressure fluctuation measuring end plug group consisting of a total of 10 pressure fluctuation measuring end plugs of 1, 2, 3, 4 and a closed end consisting of a total of 10 closed end plugs. The condenser cooling pipe leakage inspection device according to [1], further comprising an end plug group.

  [3] When the cooling pipes are arranged in a grid pattern, the pressure fluctuation measuring end plug group including a total of four pressure fluctuation measuring end plugs, one or three, and the blocking end consisting of a total of four closing end plugs. An end plug group, or a pressure fluctuation measuring end plug group consisting of a total of nine pressure fluctuation measuring end plugs, one, three, and five, and a closed end plug group consisting of a total of nine closed end plugs are also provided. The condenser condenser pipe leakage inspection device according to [1] above, wherein

  In the present invention, when inspecting the condenser cooling pipe for leakage, the pressure fluctuation measuring end plugs are grouped in a triangular shape, and the closed end plugs are gathered in a triangular shape. By using the closed end plug group, the pressure fluctuation measuring end plug and the closing end plug can be simultaneously inserted into the plurality of cooling pipes, and leakage inspection of the plurality of cooling pipes can be performed with one pressure fluctuation measuring means. The presence or absence of leakage in the cooling pipe can be easily and efficiently inspected.

It is a figure which shows one Embodiment of this invention. It is an AA arrow line view of FIG. It is a figure which shows the pressure fluctuation measurement end plug group in one Embodiment of this invention. It is a figure which shows the other example of the pressure fluctuation measurement end plug group in one Embodiment of this invention. It is a figure which shows a general condenser.

  One embodiment of the present invention will be described.

First, the condenser cooling pipe leakage inspection apparatus according to an embodiment of the present invention is a cooling system in which a cooling water leak occurs in the cooling pipe group in the condenser as shown in FIG. In order to detect the pipe, a pressure fluctuation measuring end plug communicating with a pressure fluctuation measuring means for measuring pressure fluctuation in the cooling pipe is inserted into one end of the cooling pipe, and the cooling pipe is closed at the other end of the cooling pipe. A closed end plug is inserted, and the pressure fluctuation measuring means measures the pressure fluctuation in the cooling pipe due to the outflow from the hole due to the pressure difference between the inside of the cooling pipe and the outside of the cooling pipe, thereby detecting the leakage of the cooling pipe. Although it is a condenser cooling pipe leakage inspection device, its basic concept is as follows.
(1) It is a structure that can inspect a large number of water-cooled tubes at once.
(2) The structure is compact and easy to handle so that workers can use it manually.
(3) A short-time inspection operation (for example, within 10 seconds / one place) is possible.
(4) Even when the condenser is in single-lung operation (the outside of the water-cooled tube is in a vacuum state and the inside of the cooling tube to be examined is in the atmospheric pressure state), it is completely stopped (the outside of the water-cooled tube is in the atmospheric pressure state and inside the cooling tube to be examined) Can be inspected even under atmospheric pressure conditions.

  Based on the above concept, the condenser cooling pipe leakage inspection apparatus according to this embodiment simultaneously inserts the pressure fluctuation measuring end plug and the closed end plug into a plurality of (for example, six) cooling pipes. Thus, a pressure fluctuation measurement in which a plurality of (for example, six) pressure fluctuation measuring end plugs are arranged in a triangular shape corresponding to the arrangement of the cooling pipes so that one pressure fluctuation detecting means can inspect for leakage. An end plug group and a closed end plug group in which a plurality of (for example, six) closed end plugs are grouped in a triangular shape, and the pressure fluctuation end plugs in the pressure fluctuation measurement end plug group communicate with each other. It has a structure of being.

  Hereinafter, a condenser cooling pipe leakage inspection apparatus according to this embodiment will be described with reference to the drawings.

  FIG. 1 is a view showing a condenser cooling pipe leakage inspection device according to this embodiment, and shows a state where the condenser cooling pipe leakage inspection apparatus is installed in a condenser pipe group of the condenser as shown in FIG. FIG. 2 is an AA arrow view in FIG. FIG. 3 is a perspective view showing a pressure variation measuring end plug group used in this embodiment. Here, a case is shown in which the condenser performs an inspection at a complete stop. Therefore, the outside of the water-cooled pipe is in an atmospheric pressure state, and the cooling water is also drawn out in the cooling pipe to be inspected and is in an atmospheric pressure state.

  As shown in FIGS. 1 to 3, the condenser cooling pipe leakage inspection apparatus according to this embodiment has holes 50 in the cooling pipe group 14 composed of a large number of cooling pipes 15 supported by the pipe plate 13. In order to detect the cooling pipe in which the cooling water leaks, the pressure fluctuations in the six cooling pipes 15 can be measured with the pressure gauge 41 by being inserted into one end of each of the six cooling pipes 15. The pressure fluctuation measuring end plug group 20 including the six pressure fluctuation measuring end plugs 23 and the other cooling pipe 15 are respectively inserted into the other ends of the six cooling pipes 15 and the other ends of the cooling pipes 15 are closed. And a closed end plug group 30 including six closed end plugs 33.

  As shown in FIGS. 2 and 3, for the pressure fluctuation measuring end plug group 20, six pressure fluctuation measuring end plugs 23 correspond to the cooling pipes 15 arranged in a staggered manner on the gantry 24. They are arranged in a triangular shape (1, 2, 3).

  Each pressure fluctuation measuring end plug 23 includes a hollow nozzle 21 and a rubber seal 22 that seals between the nozzle 21 and the cooling pipe 13. The tip of the nozzle 21 is inserted into the cooling pipe 15 and the nozzle 21. The rear end is connected to a hollow portion 25 provided in the gantry 24. Thus, the six pressure fluctuation end plugs 23 communicate with each other. A nipple 26 is connected to the hollow portion 25.

  The hollow portion 25 is connected via a nipple 26 to a pressure gauge pipe 42 in which a pressure gauge 41 is installed. Further, the pressure gauge pipe 42 is connected to a hose 44 for supplying compressed air from a compressor (not shown) through a universal joint 43. The hose 44 is provided with a pressure reducing valve (not shown) so that the pressure does not increase more than necessary.

  On the other hand, in the closed end plug group 30 as well, the six closed end plugs 33 correspond to the cooling pipes 15 arranged in a staggered manner on the gantry 34 in the same manner as the six pressure fluctuation measuring end plugs 23 described above. Are arranged in a triangular shape (1, 2, 3).

  Each closed end plug 33 includes a mandrel 31 and a rubber seal 32 that seals between the mandrel 31 and the cooling pipe 15. By inserting the closed end plug 33 into the other end of the cooling pipe 15, the cooling pipe 15 The other end is sealed.

  Then, by inserting the pressure fluctuation measuring end plug group 20 and the closed end plug group 30 as described above so as to face both ends of the six cooling pipes 15, the inside of the six cooling pipes 15 and the nozzles 21. The inside and the hollow part 25 form a single space (inspection space), and a predetermined pressure (for example, 0.1 MPa) from the compressor is supplied into the inspection space for a predetermined holding. By measuring the pressure fluctuation in the inspection space after time (for example, after 10 seconds) with the pressure gauge 41, it is possible to inspect whether or not the six cooling pipes 15 are leaking (the presence or absence of the holes 50).

  That is, since the outside of the water-cooled tube is in the atmospheric pressure state, if the hole 50 exists in any of the six cooling tubes 15, the compressed air flows out from the hole 50, and the pressure fluctuation (pressure drop) in the inspection space. Occurs. On the other hand, if there is no hole 50 in any of the six cooling pipes 15, pressure fluctuation (pressure drop) in the inspection space does not occur.

  If a pressure fluctuation (pressure drop) occurs in the inspection space, any of the six cooling pipes 15 has a leak, so that the six cooling pipes 15 are individually The presence or absence of leakage (the presence or absence of holes 50) is inspected to identify the cooling pipe 15 having leakage.

  On the other hand, if there is no pressure fluctuation (pressure drop) in the inspection space, there will be no leakage in any of the six cooling pipes 15, so the next six cooling pipes 15 will be inspected. Move on.

  As described above, it is possible to perform a leakage inspection when the condenser is completely stopped.

  On the other hand, when the condenser is in one-lung operation and the leakage inspection of the cooling chamber A or B is stopped, the hose 44 is disconnected from the pressure measurement pipe 42 in FIG. The pressure fluctuation in the examination space is measured using a vacuum gauge instead of the pressure gauge 41.

  That is, when the condenser is operating in one lung, the outside of the water cooling pipe is in a vacuum state, and the cooling water is drawn out to the atmospheric pressure state inside the cooling pipe to be inspected. When the hole 50 exists in any one of them, air flows out from the hole 50 and the inside of the examination space becomes negative pressure. Therefore, it is possible to detect the presence of the hole 50 in one of the six cooling pipes 15 by detecting the pressure fluctuation (pressure drop) that becomes the negative pressure with a vacuum gauge.

  Of course, if there is no hole 50 in any of the six cooling pipes 15, pressure fluctuation (pressure drop) in the inspection space does not occur.

  As described above, a leak test can be performed when the condenser is operating in one lung.

  In the above, the pressure fluctuation measuring end plug group 20 is arranged in a triangular shape with a total of six pressure fluctuation measuring end plugs 23 corresponding to the cooling pipes arranged in a staggered manner. As shown in the perspective view of FIG. 4, the pressure fluctuation measuring end plug group 20 includes one, two, three, and four pressure fluctuation measuring end plugs 23 in total. Those arranged in a triangular shape may be used.

  When the cooling pipes are arranged in a grid, the pressure fluctuation measuring end plug group 20 includes one, three, four pressure fluctuation measuring end plugs 23 arranged in a triangular shape, A total of nine pressure fluctuation measuring end plugs 23 arranged in a triangular shape are used.

  Of course, in this case, in accordance with the arrangement of the pressure fluctuation measuring end plug group 20, the closed end plug group 30 having the same closed end plug 33 is used.

  The pressure variation measuring end plug group 20 is made of metal for the parts other than the rubber 22 (nozzle 21, pedestal 24, etc.) in consideration of pressure resistance, but the weight is 1 kg or less in consideration of handling properties. It is preferable. The same applies to the closed end plug group 30.

  Here, the pressure fluctuation measuring end plug 23 and the closed end plug 33 are arranged in a triangular shape. However, if the pressure fluctuation measuring end plug 23 and the closed end plug 33 are arranged in a straight line, the pressure fluctuation measuring end plug 23 and the closed end plug 33 are arranged in a straight line. The measurement end plug group 20 and the closed end plug group 30 are long, and the handling property in the water chamber is deteriorated.

  As described above, in this embodiment, a leakage inspection apparatus having a structure that is compact and easy to handle is used to perform leakage inspection of a large number of water-cooled tubes at a time even when the condenser is in single lung operation or when it is completely stopped. It can be done in a short time of inspection work. That is, it is possible to simply and efficiently inspect for the presence or absence of leakage in the condenser cooling pipe.

  As a result, the leakage inspection work time is shortened, and it becomes possible to reduce opportunity loss and leakage inspection costs.

13 Tube Plate 14 Cooling Tube Group 15 Cooling Tube 20 Pressure Fluctuation Measurement End Plug Group 21 Nozzle 22 Rubber 23 Pressure Fluctuation Measurement End Plug 24 Mounting Base 25 Hollow Part 26 Nipple 30 Blocking End Plug Group 31 Mandrel 32 Rubber 33 Closing End Plug 34 Mounting Base 41 Pressure gauge 42 Pressure gauge piping 43 Universal joint 44 Hose 50 Hole 70 Condenser body 71 Steam turbine 72 Body 73 Tube plate 74 Cooling tube group 75a, 75b Water chamber 76 Condensate reservoir 77 Condensate outlet 80a, 80b Cooling water (seawater )
81 water vapor

Claims (3)

In order to detect cooling pipes that have holes in the condenser and have leaked cooling water, one end of the cooling pipe is used as a pressure fluctuation measuring means to measure the pressure fluctuation in the cooling pipe. A pressure fluctuation measuring end plug is connected, and a closed end plug for closing the cooling pipe is inserted into the other end of the cooling pipe, which is accompanied by an outflow from the hole due to a pressure difference between the inside of the cooling pipe and the outside of the cooling pipe. A condenser cooling pipe leakage inspection device for detecting a leakage of a cooling pipe by measuring a pressure fluctuation in the cooling pipe by the pressure fluctuation measuring means,
A plurality of pressures corresponding to the arrangement of the cooling pipes so that the presence or absence of leakage can be inspected by one pressure fluctuation detecting means by simultaneously inserting the pressure fluctuation measuring end plug and the closed end plug into the plurality of cooling pipes. comprises a variation measuring end plug pressure fluctuation measuring portion plug group gathered in a triangular shape on the platform, also a plurality of closed end plugs of the closed end plug group gathered in a triangular shape on the gantry, the pressure variation measurement The condenser cooling pipe leakage inspection device, wherein the pressure fluctuation end plugs in the end plug group communicate with each other.   When the cooling pipes are arranged in a staggered arrangement, the pressure fluctuation measuring end plug group including a total of six pressure fluctuation measuring end plugs, one, two, and three, and the closed end including a total of six closed end plugs. A plug group, or a pressure fluctuation measuring end plug group consisting of a total of 10 pressure fluctuation measuring end plugs of 1, 2, 3, 4 and a closed end plug group consisting of a total of 10 closed end plugs. The condenser cooling pipe leakage inspection device according to claim 1, comprising:   When the arrangement of the cooling pipes is a lattice arrangement, a pressure variation measuring end plug group including a total of four pressure variation measuring end plugs, one or three, and a closed end plug group including a total of four closed end plugs. Or, a pressure variation measuring end plug group consisting of a total of nine pressure variation measuring end plugs, one, three, and five, and a closed end plug group consisting of a total of nine closed end plugs are provided. The condenser cooling pipe leakage inspection device according to claim 1.

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