JP2007163003A - Method and apparatus for diagnosing blockage of heat exchanger tube - Google Patents

Abstract

It is possible to reduce labor and time required for diagnosing the presence or absence of blockage of a heat transfer tube.
A sponge ball 20 is packed into one end portion of a heat transfer tube 2 of a heat exchanger 19 and then the sponge ball 20 is brought into the heat transfer tube 2 using a pressurized air 23 having a required pressure to be ejected from an air gun 27. The heat transfer tube 2 from which the sponge ball 20 is discharged is diagnosed by observing whether or not the sponge ball 20 that has been shot is discharged from the other end of the heat transfer tube 2. On the other hand, the heat transfer tube 2 from which the sponge balls 20 are not discharged is diagnosed as being clogged with foreign matter or the like. The time required for diagnosing the blockage of all the heat transfer tubes 2 is determined immediately by determining whether or not the sponge ball 20 shot from one end is discharged from the other end. Reduce.
[Selection] Figure 1

Description

  The present invention relates to a multi-tube heat exchanger, in particular, a heat exchanger tube of a heat exchanger comprising a large number of heat transfer tubes such as a heat exchanger in a nuclear power plant or a spent fuel storage facility. The present invention relates to a method and an apparatus for diagnosing blockage of a heat exchanger heat transfer tube used for diagnosing whether or not there is a problem.

  One type of multi-tube heat exchanger that is generally used is a heat exchanger that includes a heat transfer tube bent in a U-shape in order to prevent thermal expansion of the heat transfer tube.

  FIG. 3 shows a basic configuration of a heat exchanger of the type provided with the U-shaped heat transfer tube. A large number of U-shaped heat transfer tubes 2 are arranged in the body 1 of the heat exchanger. Thus, one end portion and the other end portion of each heat transfer tube 2 are supported by being penetrated through the tube plate 3 disposed so as to close the opening side end portion of the barrel 1. A partition plate 4 is attached to the opposite side of the tube plate 3 with respect to the body 1 so as to partition the inlet side and the outlet side of each heat transfer tube 2, and the inside of the inlet plate 5 a and the outlet chamber 5 b is divided by the partition plate 4. It is set as the structure formed by providing the water chamber (water box) 5 divided into 2 (for example, refer patent document 1). As a result, the first fluid guided to the inlet chamber 5 a of the water chamber 5, for example, the cooling water 6, is introduced into the trunk 1 while being circulated through the heat transfer tubes 2 and sent to the outlet chamber 5 b. Heat is exchanged with the second fluid, for example, the fluid 7 to be cooled, so that the fluid 7 can be cooled.

  Of the heat exchangers comprising such U-shaped heat transfer tubes 2, heat exchangers used as pool water cooling system heat exchangers and condensers in nuclear power plants, or in spent fuel storage facilities As the heat exchanger used in the above, a vertical heat exchanger in which the heat transfer tubes 2 are arranged in an inverted U shape is often used, and is used in such nuclear power plants and spent fuel storage facilities. In some heat exchangers, the number of the heat transfer tubes 2 reaches several hundred to several thousand per unit.

  By the way, when foreign matter is mixed in the cooling water 6 supplied to the multi-tubular heat exchanger as described above, the foreign matter rides on the flow of the cooling water 6 from the inlet chamber 5a of the water chamber 5 and transfers the above-mentioned transmission. There is a possibility of entering the heat pipe 2, and the foreign matter that has entered may adhere to the inside of the heat transfer pipe 2 or may be blocked by being caught.

  Since the clogging of the heat transfer tube 2 due to the foreign matter as described above leads to an increase in pressure loss, it is necessary to eliminate the clogging by cleaning the inside of the heat transfer tube 2 where the clogging has occurred and removing the foreign matter. is there. Therefore, in the above-described multi-tube heat exchanger, it is necessary to diagnose whether or not each heat transfer tube 2 is clogged with foreign matter at the time of required maintenance. Furthermore, when the work of diagnosing whether or not the heat transfer tube 2 is blocked by foreign matter is separately cleaned by the foreign matter of the heat transfer tube 2, the heat transfer tube 2 blocked by the foreign matter to be cleaned is used. Needs to be specified from among a large number of heat transfer tubes 2.

  When diagnosing the presence or absence of clogging due to foreign matter in the heat transfer tube 2 with respect to the multi-tube heat exchanger as described above, conventionally, a fiberscope or the like is inserted into each heat transfer tube 2 and visually inspected. It was like that.

  A power plant condenser for condensing steam after being used for driving a steam turbine at a power plant is generally a power plant as a shell-and-tube heat exchanger as shown in FIG. A condenser 8 is used, and steam introduced into the shell (body) 10 is caused by passing a seawater 12 guided through an inlet circulating water pipe 11 through a condenser thin pipe (heat transfer pipe) 9. (Not shown) is cooled to condensate, and the seawater 12 after the cooling of the steam is sprinkled from the outlet 14 to the ocean 15 through the outlet circulation water pipe 13. is there.

  Furthermore, since the thin tube 9 of the power plant condenser 8 allows the cooling seawater 12 to pass through, if appropriate maintenance is not performed, scales, marine products, etc. adhere to the inner wall of the tube, There is a possibility that the narrow tube 9 is blocked and the cooling efficiency is lowered. Therefore, in the power plant condenser 8, it is necessary to periodically clean (clean) the condenser thin tube 9. In recent years, the condenser thin tube 9 has been washed as a normal method. Many ongoing ball cleanings have been implemented.

  This is because a cleaning ball 16 such as a sponge ball having a required flexibility is mixed in advance with the seawater 12 guided to the condenser thin tube 9 at a midway position of the inlet circulating water pipe 11, and the cleaning ball is mixed. By circulating the seawater 12 containing 16 to the condenser thin tube 9, the scales and marine products attached to the inner wall of the condenser thin tube 9 are transferred to the seawater 12 passing through the condenser thin tube 9. The condenser balls 9 are scraped off by the contained cleaning balls 16 to clean the condenser tubes 9. The cleaning ball 16 after passing through the condenser thin tube 9 is collected by the ball collector 17 from the seawater 12 sprinkled into the ocean 15 and then recirculated or collected in the ball collector 18. (For example, refer to Patent Document 2).

Japanese Utility Model Publication No. 63-197988 JP-A-11-118389

  However, as described above, for heat exchangers in which the number of heat transfer tubes 2 per unit reaches several hundred to several thousand, such as heat exchangers used in nuclear power plants and spent fuel storage facilities, To conduct a visual inspection with a fiberscope or the like for each of the heat transfer tubes 2 and diagnose the blockage of each heat transfer tube 2, for example, only a few tens of diagnoses can be made per day. A great amount of labor and time are required for the blockage diagnosis work of the heat transfer tube 2. In addition, when the heat exchanger to be inspected is installed in a radiation management area in a nuclear power plant or spent fuel storage facility, it is preferable to shorten the work time in the radiation management area as much as possible. Therefore, even in a heat exchanger having hundreds to thousands of heat transfer tubes 2 as described above, the diagnosis of the presence or absence of blockage of the heat transfer tubes 2 due to foreign matters can be efficiently performed, and the diagnosis is performed. It is desired to shorten the work time required for the operation.

  In addition, what is described in Patent Document 2 is for washing and removing scales and marine products adhering to the inner wall of the condenser thin tube 9 of the power plant condenser 8. It is not possible to diagnose the presence or absence of blockage due to foreign matter or the like in the water tube 9

  That is, in what is described in Patent Document 2, the cleaning ball 16 mixed with seawater in the inlet circulating water pipe 11 is mixed with the seawater 12 of the condenser condenser 9 of the power plant condenser 8. The number of cleaning balls 16 guided to each condenser thin tube 9 cannot be strictly controlled because it is supplied on the flow, and it has passed through each condenser thin tube 9. Since the seawater 12 including the subsequent cleaning balls 16 are collectively guided to the outlet circulating water pipe 13, there is absolutely no means for confirming the passing state of the cleaning balls 16 in the individual condenser thin tubes 9. Absent. Therefore, even if one of the condenser thin tubes 9 is blocked by a foreign substance and the circulation of the sea water 12 and the washing balls 16 in the condenser thin tubes 9 is inhibited, the sea water 12 and the washing The ball 16 avoids the condenser thin tubes 9 that are blocked by the foreign matter and passes through the other condenser tubes 9 that are not blocked. Therefore, the balls 16 are blocked by the individual condenser tubes 9. In other words, it is not possible to diagnose whether or not the condenser capillaries 9 are blocked out of all the condenser capillaries 9.

  Therefore, the present invention can easily diagnose whether all of the heat transfer tubes of the multi-tube heat exchanger are in a healthy state where no blockage occurs or a state in which blockage due to foreign matter is a concern. An object of the present invention is to provide a heat transfer tube blockage diagnosing method and apparatus that can shorten the time required and that can easily identify a heat transfer tube that is blocked by foreign matter from among a large number of heat transfer tubes. .

  In order to solve the above problems, the present invention shoots a ball of a flexible material having a required diameter from one end into a heat transfer tube in a heat exchanger by the pressure of a required fluid, and the shot ball is the other end of the heat transfer tube. To the heat exchanger tube diagnosis method for diagnosing whether the heat transfer tube is sound or whether there is a possibility of blockage due to foreign matter depending on whether it is discharged from the section, and to the heat exchanger tube of the heat exchanger A ball of a flexible material having a required diameter for insertion, and a pressure of the required fluid on the ball inserted into one end of the heat transfer tube so that the required fluid can be injected into the heat transfer tube at a required pressure. A fluid ejecting apparatus configured to be able to shoot the ball into the heat transfer tube by acting, and a ball recovery device for recovering the ball struck into the heat transfer tube from the other end Having heat The closure diagnostic apparatus exchanger heat transfer tube.

  In addition, a ball made of a flexible material with a required diameter from one end is struck into all heat transfer tubes in the heat exchanger using the pressure of the required fluid, and a heat transfer tube in which no ball is discharged from the other end of each heat transfer tube is detected. By doing so, it is set as the blockage diagnosis method of the heat exchanger heat exchanger tube which identifies the heat exchanger tube with the possibility of obstruction | occlusion by a foreign material.

  In each of the above-mentioned configurations, the ball diameter and the pressure condition of the fluid when the ball is shot into the heat transfer tube are determined by using a heat transfer tube model in a closed state in which the heat transfer tube is assumed to be blocked in advance. Is set based on the boundary conditions when the ball is caught and passed by the closed portion, and the ball diameter and the condition of the fluid pressure for injecting the ball into the heat transfer tube by injecting from the fluid injection device Is set based on the boundary condition when the ball is hooked and passed by using the model of a closed heat transfer tube that is assumed to cause the heat transfer tube to be blocked in advance. And

  Furthermore, in each of the above-described configurations, a method of using pressurized air as a fluid for shooting a ball into a heat transfer tube, and a fluid ejecting apparatus including a pressure regulating valve and a pressure gauge on an air supply line for introducing the pressurized air And a nozzle for injecting pressurized air in close contact with one end of the heat transfer tube of the heat exchanger at the tip of the air supply line, and for starting and stopping the supply of pressurized air And an operation unit is attached to an air gun.

According to the blockage diagnosis method and apparatus for a heat exchanger heat transfer tube of the present invention, the following excellent effects are exhibited.
(1) A ball made of a flexible material having a required diameter from one end is struck into a heat exchanger tube in a heat exchanger by the pressure of a required fluid, and whether or not the struck ball is discharged from the other end of the heat transfer tube. Heat exchanger heat transfer tube blockage diagnosis method for diagnosing whether the heat transfer tube is healthy or possibly clogged by foreign matter, and a flexible diameter required for insertion into the heat exchanger tube of the heat exchanger The ball is transferred by applying the pressure of the required fluid to the ball inserted into one end of the heat transfer tube so that the required fluid can be injected into the heat transfer tube at a required pressure. Closure of heat exchanger heat transfer tube having a configuration comprising a fluid ejecting device capable of being shot into a heat tube and a ball recovery device for recovering the ball shot into the heat transfer tube from the other end. As a diagnostic device Therefore, just observing whether or not the ball shot from one end of the heat transfer tube is discharged from the other end of the heat transfer tube, whether the heat transfer tube is healthy or is clogged Can be easily diagnosed. Furthermore, the time required for the blockage diagnosis per heat transfer tube can be significantly reduced, for example, from several seconds to several tens of seconds, as compared with a conventional fiberscope diagnosis operation. Therefore, even in a heat exchanger having hundreds to thousands of heat transfer tubes, the work time required for diagnosing the presence or absence of blockage in the heat transfer tubes can be greatly reduced. When the heat exchanger to be installed is installed in the radiation management area, the working time in the radiation management area can be greatly shortened.
(2) A ball made of a flexible material having a required diameter from one end is struck into all heat transfer tubes in the heat exchanger using the pressure of the required fluid, and among the heat transfer tubes, a heat transfer tube in which the balls are not discharged from the other end By detecting the heat transfer tubes that are likely to be blocked by foreign matter, it is possible to easily identify the heat transfer tubes that are likely to be blocked among all the heat transfer tubes. (3) The ball is blocked by using a model of a closed heat transfer tube that is assumed to cause the blockage of the heat transfer tube in advance with respect to the diameter of the ball and the fluid pressure conditions when the ball is shot into the heat transfer tube. By setting based on the boundary conditions when the part is caught and passed, it is possible to appropriately diagnose whether or not the heat transfer tube is blocked by shooting the ball into the heat transfer tube.
(4) By using pressurized air as a fluid for shooting the ball into the heat transfer tube, it can be used easily, and the post-treatment of the fluid discharged together with the ball passing through the heat transfer tube is easy. Can be. Further, in a nuclear power plant, it is possible to use pressurized air that is supplied to each location for regular use.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows an embodiment of a heat exchanger heat transfer tube blockage diagnosing method and apparatus according to the present invention. A ball made of a flexible material to be inserted into the heat transfer tube 2 of a heat exchanger 19 to be subjected to blockage diagnosis. For example, a sponge ball 20, a fluid ejecting device 21 that can inject a required fluid at a required pressure from one end (one end) on the inlet side or the outlet side of the heat transfer tube 2, and the above The sponge ball 20 is disposed at one end portion of the heat transfer tube 2 to be diagnosed for blockage as a configuration comprising a ball recovery device 22 for recovering the sponge ball 20 passing through the heat transfer tube 2 and discharged from the other end portion. After the insertion, the fluid ejecting device 21 injects the required fluid from the one end portion side of the heat transfer tube 2 at a required pressure to shoot the sponge ball 20 into the heat transfer tube 2, and the sponge ball thus struck is injected. Based on whether or not 20 is discharged from the other end of the heat transfer tube 2 toward the ball collector 22, the heat transfer tube 2 is in a healthy state where there is no risk of blockage due to foreign matter or the like, Make sure that you are in a state of concern.

  Further, the sponge balls 20 are sequentially fired from one end side to all the heat transfer tubes 2 in the heat exchanger 19 in the same manner as described above. The heat transfer tube 2 from which 20 is not discharged is specified as the heat transfer tube 2 in which the occurrence of clogging due to foreign matter is a concern.

  Details will be described below.

  The heat exchanger is shown as a vertical type with the same heat transfer tubes 2 as shown in FIG. 3 arranged in an inverted U shape.

  The fluid ejected from the fluid ejecting device 21 to shoot the sponge ball 20 against the heat transfer tube 2 is easy to use and the sponge ball 20 passes through the heat transfer tube 2 and is discharged from the other end. Considering the post-treatment of the fluid that is sometimes discharged together with the sponge ball 20, for example, the pressurized air 23 supplied for regular use at each place in a nuclear power plant is used.

  The fluid ejecting apparatus 21 adjusts the pressure air 23 supplied from a pressure air supply unit (not shown) to a desired pressure, and then can be used to shoot the sponge ball 20 into the heat transfer tube 2. In order to do so, a pressure regulating valve 25 and a pressure gauge 26 are provided in this order from the upstream side on an air supply line 24 that is connected to the pressurized air supply unit to guide the pressurized air 23. Further, a nozzle 28 for injecting the pressurized air 23 into the heat transfer tube 2 in a state where the air supply line 24 is pressed against and closely adhered to the opening on the one end side of the heat transfer tube 2 of the heat exchanger 19. And an air gun 27 having an open / close lever 29 as an operation unit for operating the supply start and stop of the pressurized air 23 is connected. Thus, after adjusting the air pressure detected by the pressure gauge 26 to the desired pressure by operating the pressure adjusting valve 25, the nozzle 28 of the air gun 27 is placed in the opening on one end side of the heat transfer tube 2. By opening the opening / closing lever 29 in a close contact state, the pressurized air 23 having the desired pressure can be injected into the heat transfer tube 2. Further, the air gun 27 is preferably provided with a handle 30 for facilitating the work of bringing the nozzle 28 into close contact with the opening on the one end side of the heat transfer tube 2.

  The diameter of the sponge ball 20 and the pressure of the pressurized air 23 injected into the heat transfer tube 2 from the air gun 27 are selected as follows.

  That is, when the heat transfer tube 2 is blocked by foreign matter or the like, the air flow is not completely blocked so that the air flow is completely blocked. If possible, the sponge ball 20 can be shot into the heat transfer tube 2 using the pressure of the pressurized air 23.

  At this time, if the diameter of the sponge ball 20 is smaller than the inner diameter of the heat transfer tube 2, a gap is formed between the inner peripheral surface of the heat transfer tube 2 and the outer periphery of the sponge ball 20, and the pressurized air 23 blows through the gap. This is not preferable because it may cause Therefore, the diameter of the sponge ball 20 is set to be at least larger than the inner diameter of the heat transfer tube 2 so that the sponge ball 20 is inserted into the heat transfer tube 2 in a compressed state. The heat transfer tube 2 can be brought into close contact with the inner peripheral surface.

  Furthermore, under the condition that the diameter of the sponge ball 20 is set within a range that is at least larger than the inner diameter of the heat transfer tube 2 as described above, the size of the sponge ball 20 is determined by the behavior of the sponge ball 20 in the closed portion of the heat transfer tube 2. Affects. That is, when the diameter of the sponge ball 20 is relatively small, the compressed state is weak because the sponge ball 20 is less crushed when the sponge ball 20 is inserted into the heat transfer tube 2. Since this weakly compressed sponge ball 20 is in a state in which further compression is easily allowed, when the sponge ball 20 is shot into the heat transfer tube 2 by the pressurized air 23 injected from the air gun 27, Since the sponge ball 20 that has reached the closed portion in the heat transfer tube 2 is easily compressed and deformed into a shape that can pass through the closed portion, the sponge ball 20 tends not to be caught on the closed portion.

  On the other hand, the larger the diameter of the sponge ball 20 is, the more compressed it is simply inserted into the heat transfer tube 2, and thus the more strongly the compression becomes difficult. If it is shot into, it tends to be easily caught on the closed portion of the heat transfer tube 2. If the diameter of the sponge ball 20 is too large, the sponge ball 20 packed in the heat transfer tube 2 may not be moved by the pressure of the pressurized air 23.

  In addition, a change in the pressure of the pressurized air 23 used when the sponge ball 20 is shot into the heat transfer tube 2 also affects the behavior of the sponge ball 20 in the closed portion in the heat transfer tube 2. That is, when the pressure of the pressurized air 23 is low, when the sponge ball 20 shot into the heat transfer tube 2 reaches the closed portion, the force to push the sponge ball 20 against the closed portion is weak. The sponge ball 20 tends to be caught on the closed portion of the heat transfer tube 2. On the other hand, when the pressure of the pressurized air 23 is high, the sponge ball 20 is strongly pushed into the closed portion, so that it tends not to be caught in the closed portion. If it is too high, the sponge ball 20 will pass through the heat transfer tube 2 even if the heat transfer tube 2 is blocked.

  Therefore, in the present invention, a model of the heat transfer tube 2 having an inner diameter and a curved shape similar to those of the heat transfer tube 2 of the heat exchanger 19 to be subjected to blockage diagnosis in advance is used. The heat transfer tube under the closed state is formed by forming a closed state due to a foreign material, for example, a vinyl sheet, a wire, a piece of heat insulating material, a stick-shaped foreign material, etc. 2 when the sponge ball 20 is shot into the block 2 when the sponge ball 20 is caught by the foreign matter in the heat transfer tube 2 and when the sponge ball 20 passes through the closed portion. While obtaining the pressure condition of the air 23, the other end of the model of the heat transfer tube 2 similar to the above is provided with a blocking plate for partially limiting the flow area, for example, as shown in FIG. 2 channels on the outer peripheral side As shown in FIG. 2 (b), the ring-shaped blocking plate 31 that can restrict the flow passage area at a predetermined ratio by narrowing down, or close to one side of the flow passage of the heat transfer tube 2 along the string. The flow path of the heat transfer tube 2 can be closed as shown in FIG. 2 (c), as shown in FIG. 2 (c). By attaching a blocking plate 33 that can limit the flow passage area at a predetermined ratio by changing the thickness of the cross portion in a cross shape in the vertical and horizontal directions through a mounting member (not shown), the heat transfer tube 2 When the sponge ball 20 is shot by using the pressurized air 23 from one end of the model of the heat transfer tube 2 in a state in which the flow path is set to a known predetermined blocking rate, the sponge ball 20 is blocked by the blocking plates 31 and 32. , 33 is caught in the installation part Quito, to determine a boundary become under a pressure of diameter and pressurized air 23 sponge ball 20 as it passes through. Thereafter, by comparing both conditions, when the sponge ball 20 struck by the pressurized air 23 comes to be caught by the closed portion when a closed portion due to foreign matter is generated in the heat transfer tube 2. As for the condition of the diameter of the sponge ball 20 and the pressure of the pressurized air 23, the percentage of the area ratio of the heat transfer tube 2 using the closing plates 31, 32, 33 is determined to be the same. Then, the respective conditions are quantified. As a result, the boundary conditions regarding the diameter of the sponge ball 20 and the pressure of the pressurized air 23 when the sponge ball 20 passes and gets caught through the blockage portion due to the foreign matter are, for example, the block plates 31 and 32 having a blockage rate of 10%. , 33 is used to close the heat transfer tube 2 in the same manner as the boundary conditions regarding the diameter of the sponge ball 20 and the pressure of the pressurized air 23 when the sponge ball 20 passes through the closed portion and when it is caught. The boundary condition for determining whether or not the heat transfer tube 2 is blocked by a foreign substance is set when the blocking plates 31, 32 and 33 having a blocking rate of less than 10% are attached to the heat transfer tube 2. The sponge ball 20 can pass through the heat transfer tube 2, but when the blocking plates 31, 32, 33 having a blocking rate of 10% or more are attached to the heat transfer tube 2, the sponge ball 20 cannot pass through. So that defined as a condition of a pressure of diameter and pressurized air 23 sponge ball 20 as referred to.

  Specifically, for example, for the heat transfer tube 2 having an inner diameter of 17 mm, a sponge ball 20 having a diameter of about +1 mm to +10 mm (about + 6% to + 60%) is used, and the pressure condition of the pressurized air 23 to be used is It is set to 0.1 MPa to 0.5 MPa.

  The ball recovery unit 22 adds the sponge ball 20 passing through the heat transfer tube 2 and discharged from the other end of the heat transfer tube 2 together with the sponge ball 20 from the other end of the heat transfer tube 2. It can be separated from the compressed air 23 and collected. For example, a screen 35 having a required mesh sufficiently smaller than the diameter of the sponge ball 20 is provided at the middle in the vertical direction in the box-shaped container 34 having a required height dimension opened at the upper end. It is made to incline and attach so that the position of one side part may become low. Further, in order to facilitate the removal of the sponge ball 20 placed on the screen 35 from the box-shaped container 34, the side wall of the box-shaped container 34 corresponding to one side portion of the screen 35 corresponding to the low position is provided. A ball outlet 36 with an open / close door for collecting the sponge balls 20 is provided at a position immediately above the screen 35 mounting position. Further, an air outlet 37 is provided at a required position at the lower end of the box-shaped container 34 so that a local exhaust fan 38 can be connected. As a result, the local exhaust fan 38 connected to the air outlet 37 is constantly exhausted, and the upper end opening of the box-shaped container 34 is arranged at a position below the other end of the heat transfer tube 2 that performs blockage diagnosis. Try to make it in a state of letting it go. As a result, the sponge ball 20 and the pressurized air 23 passing through the heat transfer tube 2 and discharged from the other end are guided into the box-shaped container 34, and the sponge ball 20 is received on the screen 35, After separating from the pressurized air 23 passing through 35, the sponge balls 20 collected on the ball outlet 36 side due to the inclination of the screen 35 can be collected from the ball outlet 36. On the other hand, the pressurized air 23 that has passed through the screen 35 is guided to the local exhaust fan 38 from the air outlet 37, thereby preventing the possibility of backflow.

  Other components that are the same as those shown in FIG.

  In the case of using the heat exchanger heat transfer tube blockage diagnosing device of the present invention having the above configuration, first, the water chamber 5 (see FIG. 3) of the heat exchanger 19 is emptied, and then an operator is placed in the water chamber. The sponge balls 20 are inserted into one end portions of all the heat transfer tubes 2, respectively. Next, the ball collector 22 is arranged at a position below the other end of the heat transfer tube 2 and the local exhaust fan 38 connected to the ball collector 22 is operated so that the exhaust can be continuously performed. In this state, for example, the workers become a set of two people, and after confirming that a certain heat transfer tube 2 that will perform the shooting operation of the sponge ball 20 from now on is confirmed by using the required communication means, The operator presses the nozzle 28 of the air gun 27 against one end of the certain heat transfer tube 2 in which the sponge ball 20 is packed, and then operates the open / close lever 29 to operate the sponge ball 20 with the pressurized air 23. Shooting into the heat transfer tube 2 is performed. At this time, the other worker monitors whether or not the sponge ball 20 is discharged from the other end of the same heat transfer tube 2. As a result, when the sponge ball 20 is discharged, it can be determined that the heat transfer tube 2 has a blocking rate of 10% or less or is in a healthy state without blocking by a foreign substance, while the sponge ball 20 is not discharged. Therefore, it can be determined that the heat transfer tube 2 is clogged with a clogging rate of 10% or more, or that there is a fear of clogging with foreign matter. When the heat transfer tube 2 is healthy, the time required for the sponge ball 20 shot from one end to pass through the heat transfer tube 2 and be discharged from the other end is within one second.

  In addition, the other worker contacts the one worker about the result of whether or not the sponge ball 20 has been discharged, and the one worker has performed the work of shooting the sponge ball 20. If a rubber plug (not shown) color-coded according to the result of whether or not the sponge ball 20 has been discharged is inserted into one end of the mark 2 to mark it, the rubber plug that becomes the mark, etc. It is possible to easily determine whether the heat transfer tube 2 is healthy or the heat transfer tube 2 is likely to be blocked.

  Thereafter, for all the heat transfer tubes 2, the sponge balls 20 are shot from one end side in the same manner as described above, and it is monitored whether the sponge balls 20 are discharged from the other end portions of the heat transfer tubes 2. The operation of attaching a mark with a rubber plug or the like of the color corresponding to the result to one end of the heat transfer tube 2 is sequentially repeated.

  Thereafter, if the color of a mark such as a rubber stopper attached to one end of each heat transfer tube 2 is visually observed, among all the heat transfer tubes 2, there is a possibility of blockage among the heat transfer tubes 2. 2 can be easily identified at a glance. Further, as described above, the one worker who performs the operation of shooting the sponge ball 20 from one end side of the heat transfer tube 2 using the air gun 27 performs the above operation for each heat transfer tube 2 in which the sponge ball 20 has been shot. If a rubber plug or the like color-coded according to the discharge result of the ball 20 is marked, it can be easily confirmed which heat transfer tube 2 has been fired by the sponge ball 20, so that The occlusion diagnosis work can be reliably performed on the heat pipe 2.

  Thus, according to the present invention, the sponge ball 20 having a required diameter is shot from the one end of the heat transfer tube 2 by the pressurized air 23 having the required air pressure, and the above-mentioned shot is shot from the other end of each heat transfer tube 2. By simply observing whether the sponge ball 20 is discharged, it is possible to easily diagnose whether the heat transfer tube 2 is healthy or there is a risk of blockage. Since the time required for passage is less than 1 second, the time required for blockage diagnosis per heat transfer tube 2 is, for example, several seconds to several tens of seconds, which is significantly reduced compared to the conventional fiberscope diagnosis work. can do. Therefore, even in the heat exchanger 19 having hundreds to thousands of heat transfer tubes 2, the work time required for diagnosing the presence or absence of blockage in the heat transfer tubes 2 can be greatly reduced. Therefore, when the heat exchanger 19 to be diagnosed is installed in the radiation management area, the working time in the radiation management area can be greatly shortened.

When the heat transfer tube 2 is diagnosed that the sponge ball 20 shot from one end side is not discharged from the other end portion and there is a risk of blockage after the blockage diagnosis work is performed, the heat transfer tube 2 Only, the fiberscope is used again to visually inspect the inside of the heat transfer tube 2, particularly where the sponge ball 20 is stopped. What is necessary is just to confirm whether it is because of the obstruction | occlusion by presence.
When the presence of foreign matter can be confirmed by this visual inspection and the foreign matter is likely to be easily removed, for example, the sponge ball 20 is made to act by applying a higher air pressure to the sponge ball 20. It is only necessary to extrude and eliminate. Further, foreign matter that cannot be pushed out even by the sponge ball 20 subjected to the high pressure, or foreign matter found by visual inspection with a fiberscope cannot be pushed out and removed even if high air pressure is applied to the sponge ball 20. If it is, the conventional method for removing foreign matter in the piping, such as flowing water from the outlet side of the heat transfer tube 2 to the inlet side, is appropriately performed to remove the foreign matter in the heat transfer tube 2. What is necessary is just to make it remove.

  The present invention is not limited to the above-described embodiment. Prior to the operation of shooting the sponge ball 20, first, only air is injected into the heat transfer tube 2 to distribute the air in the heat transfer tube 2. The state may be confirmed, and in this way, it is possible to avoid the possibility that the sponge ball 20 is further pushed into the heat transfer tube 2 that is in a completely closed state so that air circulation is prevented. .

  The diameter of the sponge ball 20 and the pressure of the pressurized air 23 used to shoot the sponge ball 20 into the heat transfer tube 2 are the same as the inner diameter of the heat transfer tube 2 of the heat exchanger 19 that is the subject of blockage diagnosis and the heat transfer tube 2. Considering the shape of the heat transfer tube 2 such as the longitudinal curve shape and the type and size of foreign matter that may enter the heat transfer tube 2 and block the inside of the heat transfer tube 2, Using the model of the heat exchanger tube 2 of the heat exchanger 19, the boundary condition when the sponge ball 20 passes through and is caught when the foreign matter enters the heat transfer tube 2 and the blockage occurs is When the heat transfer tube 2 is closed using a required closing plate having a known closing rate, the sponge ball 20 can pass through when the heat transfer tube 2 is quantified, and when it falls below the quantified predetermined closing rate. If the blockage rate is higher than this, the sponge ball 20引掛Ru so on, it is sufficient to appropriately select the pressure of the diameter and pressurized air 23 sponge ball 20. Further, if the ball is made of a flexible material, a material other than sponge may be used. Even if the material is a sponge, the flexibility of the ball is different from that of the sponge ball 20, or when a ball of a material different from the sponge ball 20 is used, the flexibility of the ball is also increased in the heat transfer tube 2. It influences the behavior of the ball in the closed portion, and the higher the flexibility, the easier it is to pass through the closed portion, while the lower the flexibility, the easier it is to catch on the closed portion. Therefore, when the ball actually used is clogged with foreign matter in the heat transfer tube 2 in the same manner as described above, the selection of the ball diameter and the air pressure to be caught on the clogged portion is selected. You just have to do it.

  In the above description, the heat transfer tube 2 is arranged in an inverted U-shape and applied to the heat exchanger 19 in which the openings at both ends of the heat transfer tube 2 face downward. The arrangement may be a letter-shaped arrangement, or may be applied to a multi-tube heat exchanger having a heat transfer pipe other than the U-shape. In this case, the sponge ball 20 and the pressurized air 23 that have passed through the heat transfer tube 2 may be guided to the ball collector 22 via a desired duct or the like.

  When performing blockage diagnosis of the heat transfer tube 20 of the heat exchanger 19 installed in the radiation management area, it is preferable that the configuration of the apparatus carried into the radiation management area is not increased in size and complexity, but general heat exchange is performed. When the container 19 is a target for blockage diagnosis, an automatic loading device that can automatically load the sponge balls 20 one by one may be provided in the nozzle 28 portion of the air gun 27. Further, if the sponge ball 20 is provided with a code that can identify which heat transfer tube 2 has been shot, for example, a serial number or the like, an operator can make all the heat transfer tubes 2 alone. After finishing the operation of shooting the sponge ball 20 from one end of the tube, the code of the sponge ball 20 that passes through the sound heat transfer tube 2 and is collected in the ball collection device 22 is confirmed. In addition, the heat transfer tube 2 that may be blocked without the sponge ball 20 being discharged may be specified. Further, the ball recovery device 22 is provided with a partition that is individually partitioned so as to correspond to the arrangement of the other end portions of the heat transfer tubes 2, and the sponge ball 20 is shot from one end portion of all the heat transfer tubes 2. After completing the above, it may be possible to identify the heat transfer tube 2 having the possibility of blockage where the sponge ball 20 is not discharged from the position of the section where the sponge ball 20 is not collected by the ball collecting unit 22.

  In the above, the pressurized air 23 is shown as a fluid used to shoot the sponge ball 20 into the heat transfer tube 2, but if there is no inconvenience such as eroding the heat transfer tube 2, gas other than the pressurized air 23, May use a liquid such as water. In the case of using a liquid, a tank for recovering the liquid may be connected to the bottom of the ball recovery device 22, and the liquid in the tank is further ejected from the nozzle at a required pressure. What is necessary is just to equip the fluid injection mechanism which can be circulated and used for the shot of the sponge ball 20 to the heat exchanger tube 2.

  Of course, the present invention may be applied to heat exchangers other than nuclear power plants and radioactive waste storage facilities, and various changes can be made without departing from the scope of the present invention.

It is the schematic which shows one Embodiment of the blockage diagnosis method and apparatus of the heat exchanger heat exchanger tube of this invention. (A), (b), and (c) both artificially form a closed state in the heat transfer tube model in order to determine the diameter of the sponge ball used in the apparatus of FIG. 1 and the pressure condition of the pressurized air. The example of the obstruction board used for this is shown. It is a general | schematic cutting side view which shows an example of the multitubular heat exchanger which has a U-shaped heat exchanger tube. It is the schematic which shows the ball | bowl cleaning method conventionally used in order to wash | clean the thin tube of a power station condenser.

Explanation of symbols

2 Heat transfer tube 19 Heat exchanger 20 Ball (sponge ball)
21 Fluid injection device 23 Pressurized air (fluid)
24 Air supply line 25 Pressure adjustment valve 26 Pressure gauge 27 Air gun 28 Nozzle 29 Opening / closing lever (operation part)

Claims (7)

  The heat transfer tube in the heat exchanger is struck with a ball of a flexible material having a required diameter from one end by the pressure of the required fluid, and the heat transfer tube is determined by whether or not the struck ball is discharged from the other end of the heat transfer tube. A method for diagnosing the blockage of a heat exchanger heat transfer tube, characterized in that it is diagnosed whether the state is healthy or is in a state where there is a possibility of blockage due to foreign matter.   A ball made of a flexible material with a required diameter from one end is struck into all heat transfer tubes in the heat exchanger using the pressure of the required fluid, and a heat transfer tube in which the balls are not discharged from the other end is detected among the heat transfer tubes. A heat exchanger heat transfer tube blockage diagnosing method, characterized in that a heat transfer tube that is likely to be blocked by foreign matter is identified.   The ball is caught on the closed part by using the model of the closed heat transfer tube that is assumed to cause the blockage of the heat transfer tube in advance as to the condition of the diameter of the ball and the fluid pressure when the ball is shot into the heat transfer tube. 3. The method for diagnosing blockage of a heat exchanger heat transfer tube according to claim 1 or 2, wherein the blockage is set based on a boundary condition between when the heat exchanger is passed and when it passes.   The method for diagnosing blockage of a heat exchanger heat transfer tube according to claim 1, 2 or 3, wherein pressurized air is used as a fluid for shooting a ball into the heat transfer tube.   A ball made of a flexible material having a required diameter to be inserted into the heat transfer tube of the heat exchanger, and the above-mentioned fluid inserted into one end of the heat transfer tube so that the required fluid can be injected into the heat transfer tube with the required pressure. A fluid ejecting device configured to allow the ball to be shot into the heat transfer tube by applying the pressure of the required fluid to the ball, and a ball recovery for recovering the ball shot into the heat transfer tube from the other end A heat exchanger heat transfer tube blockage diagnosing device, characterized in that it has a configuration comprising a heat exchanger.   The diameter of the ball and the condition of the pressure of the fluid to be ejected from the fluid ejecting device to shoot the ball into the heat transfer tube are preliminarily determined using a model of the heat transfer tube in a closed state that is assumed to cause the heat transfer tube to be blocked in advance. The blockage diagnosis device for a heat exchanger heat exchanger tube according to claim 5, wherein the blockage diagnosis device is set based on boundary conditions between when the ball is hooked on the blockage portion and when the ball passes through the blockage portion.   The fluid ejecting device is provided with a pressure regulating valve and a pressure gauge on an air supply line for introducing pressurized air, and is further in close contact with the end of the heat transfer tube of the heat exchanger at the tip of the air supply line. The heat exchanger heat transfer tube according to claim 5 or 6, wherein an air gun comprising a nozzle for injecting air and an operation unit for operating start and stop of supply of pressurized air is attached. Occlusion diagnostic device.

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