JP2010014448A - Damage monitoring sensor and damage monitoring method - Google Patents

Abstract

[PROBLEMS] To directly monitor the actual damage state of a monitored device due to corrosion, cracking, erosion / corrosion, etc. without requiring an electric circuit and a measuring device, and the safety of the monitored device. A damage monitoring sensor and a damage monitoring method capable of ensuring
A damage monitoring sensor (3) includes a body (4) whose inside is a reagent container (4b) and a reagent container (4b) that is housed in the reagent container (4b) and reacts with a fluid or a substance contained in the fluid to cause at least one of discoloration and light emission. The reagent 5 to be presented, the monitoring window 7 provided on the top of the body 4, the opening 4 c formed on the bottom of the body 4, and the opening 4 c are provided in the opening 4 c to allow the fluid to enter and protect the reagent 5. A protective film 6 is provided, and the protective film 6 is inserted and fixed in an insertion hole provided in the wall of the monitoring target device so as to face the bottom of the insertion hole.
[Selection] Figure 2

Description

  The present invention relates to a damage monitoring sensor and a damage monitoring method for monitoring a damage state due to corrosion, cracking, erosion / corrosion, and the like of a device to be monitored.

  Corrosion, cracks, erosion, corrosion, etc. may occur due to the action of the fluid contained or circulated inside, for example, pipes that circulate water vapor or water, etc. It is desirable to monitor how much damage has occurred inside the pipe due to erosion and corrosion, for example, how much thinning of the pipe pipe wall has occurred.

  As one of such damage monitoring methods, a sample is provided in the furnace of a boiler, current is passed through this sample, the voltage at both ends of the sample is measured, and the occurrence of corrosion, corrosion amount, and corrosion rate are determined from the change in electrical resistance. There is known a method for detecting the above (for example, see Patent Document 1).

  As another damage monitoring method, the sensor head tip surface of the ultrasonic sensor is placed in contact with the surface of the high-temperature structure via a soft buffer metal plate, and then the sensor head is directed to the surface of the high-temperature structure. A method is known in which a soft buffer metal plate is plastically deformed by pressing and attached, an ultrasonic sensor is attached, and the occurrence of thinning, cracking, etc. is monitored by monitoring ultrasonic echoes ( For example, see Patent Document 2).

  As another damage monitoring method, a method is known in which a conductive circuit is provided inside or on the surface of a ceramic sintered body and the life of the sintered body is predicted based on a change in resistance value of the conductive circuit (for example, (See Patent Document 3).

As another damage monitoring method, two or more kinds of metal electrodes having different components and / or compositions are provided at one or more parts of a moving body, at least a part of which is made of a metal material, There is known a method of continuously or intermittently measuring a current or potential difference between electrodes due to an electrical short circuit (for example, see Patent Document 4).
JP-A-6-147404 JP-A-11-304777 JP-A-6-102223 JP-A-2005-134162

  Among the conventional methods described above, a method in which a sample is provided in the furnace of a boiler and the occurrence of corrosion, the amount of corrosion, and the corrosion rate are detected from the change in the electrical resistance of the sample is indirectly detected from the change in the electrical resistance of the sample. In addition, since the corrosion amount of the boiler piping is evaluated, there is a problem that the corrosion thinning amount of the actual piping is not known. Moreover, an electric circuit and a measuring device are required to measure the electrical resistance of the sample.

  Further, in the above-described method of monitoring ultrasonic echoes using an ultrasonic sensor, a soft buffer metal plate is adopted as a contact medium indispensable for ultrasonic flaw detection, and it is going to be used at a high temperature for a long time. However, a medium having good ultrasonic transmission is a substance such as water or jelly, and it is expected that the detection sensitivity of ultrasonic flaw detection is considerably lowered by employing a soft buffer metal plate. Further, when monitoring the echo of an ultrasonic wave, there is a risk that a rust film adhering to the surface of the base material is mistakenly detected as the base material. In addition, this method requires an ultrasonic sensor, a measuring device, and an electric circuit that connects between them.

  Further, in the above-described method of providing a conductive circuit inside or on the surface of the ceramic sintered body and predicting the life of the sintered body based on a change in the resistance value of the conductive circuit, the conductive body is preliminarily formed in or inside the ceramic sintered body. It is necessary to provide a circuit, and an electric circuit and a measuring device for measuring the resistance value change of the conductive circuit are required.

  Furthermore, also in the method of continuously or intermittently measuring the current or potential difference between two or more kinds of metal electrodes described above, an electric circuit and a measuring device for measuring the current or potential difference between the metal electrodes are required. .

  The present invention has been made in response to the above-described conventional circumstances, and directly describes the actual damage state of the monitored device due to corrosion, cracking, erosion, corrosion, etc. without requiring an electric circuit and a measuring device. It is an object of the present invention to provide a damage monitoring sensor and a damage monitoring method that can be monitored automatically and can ensure the safety of monitored equipment.

  The damage monitoring sensor according to the present invention is a damage monitoring sensor for monitoring a damage state inside a wall portion that partitions an inside and outside of a device to be monitored, where fluid is accommodated or circulated, and is formed in a cylindrical shape. A body having a reagent container for accommodating a reagent inside, a reagent housed in the reagent container and reacting with the fluid or a substance contained in the fluid to exhibit at least one of color change and luminescence; A monitoring window for monitoring the state of the reagent in the reagent storage unit provided at the top of the body; an opening formed at the bottom of the body and allowing the fluid to enter the reagent storage unit; A protective film that is provided in the opening and allows the fluid to enter and protects the reagent, and the protective film faces the bottom of the insertion hole in the insertion hole provided on the wall from the outside. like When the inside of the wall is damaged and the fluid enters the reagent container, the inside of the wall can be detected by at least one of discoloration and light emission of the reagent. It is characterized by.

  According to the present invention, it is possible to directly monitor the actual damage state of a monitored device due to corrosion, cracking, erosion, corrosion, or the like without requiring an electric circuit and a measuring device. Can be secured.

  Hereinafter, embodiments of the damage monitoring sensor and the damage monitoring method of the present invention will be described with reference to the drawings.

  FIG. 1 is a flowchart for explaining a damage monitoring method according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a wall portion of a monitoring target device in which corrosion, cracking, erosion, corrosion, or the like occurs. Show. In Fig.1 (a), the upper side of the wall part 1 is the inside of the monitoring object apparatus in which the fluid is accommodated or distribute | circulated, and the lower side is the exterior. That is, the wall part 1 partitions the inside of the monitoring object apparatus in which the fluid is accommodated or distribute | circulated from the exterior.

  As shown in FIG. 1 (b), a predetermined thickness not less than the thickness at which the monitored device is structurally problematic from the outside (lower side in FIG. 1 (b)) on the wall 1 of the monitored device. 1 is provided, and as shown in FIG. 1 (c), a damage monitoring sensor 3 is inserted into the insertion hole 2 and fixed. In the present embodiment, a screw 2 a is formed on the side surface in the charging hole 2.

  In the present embodiment, the damage monitoring sensor 3 is configured as shown in FIG. That is, the damage monitoring sensor 3 includes a body 4 made of a metal material having good corrosion resistance and heat resistance (for example: pure iron, pure copper, Cr alloy, Ni alloy, Co alloy, Cu alloy, etc.) and having a substantially cylindrical shape. It has. A screw 4a is formed on the outer surface of the body 4. The screw 2a on the inner side surface of the insertion hole 2 shown in FIG. 3 can be fixed. The damage monitoring sensor 3 may be fixed to the charging hole 2 by welding.

  A space is formed inside the body 4, and this space serves as a reagent container 4 b. A solid or powder reagent 5 is accommodated in the reagent accommodating portion 4b. Further, an opening 4 c is formed at the bottom of the body 4 (upper side in FIG. 2), and this opening 4 c is closed by a protective film 6. This protective film 6 has an action of allowing the fluid contained in or distributed in the monitoring target device to enter the reagent containing portion 4 b and protecting the reagent 5.

  A monitoring window 7 is provided at the top of the body 4 (lower side in FIG. 2), and the state of the reagent 5 in the reagent container 4b can be observed from the outside through the monitoring window 7. ing. The monitoring window 7 is preferably made of tempered glass or quartz glass having excellent heat resistance, pressure resistance, and corrosion resistance.

  The reagent 5 reacts with the fluid or a substance contained in the fluid when the fluid accommodated or distributed in the monitoring target device enters the reagent accommodating portion 4b via the protective film 6, and changes color. It exhibits at least one of light emission. In the present embodiment, the fluid accommodated or distributed in the monitoring target device includes at least moisture such as water vapor, water, and aqueous solution, and the reagent 5 includes a substance that reacts with water. The specific example of the substance which the reagent 5 contains is shown below.

A substance for absorbing moisture, for example, calcium chloride (CaCl ₂ ), lithium chloride (LiCl) solid or powder. A substance that changes color by absorbing moisture, for example, a solid or powder of cobalt chloride (CoCl ₂ ). Solid or powder of a substance that absorbs moisture and emits light, for example, sodium hydroxide, luminol, an oxidizing agent (for example: potassium permanganate, potassium dichromate), a catalyst having an iron complex (for example: hemoglobin, hemin) Etc.

For example, the calcium chloride powder contained in the reagent 5 absorbs water vapor, water, and a solution containing water in the environment, and is liquefied and liquefied by the following reaction formula.
CaCl ₂ (powder) + 2H ₂ O → CaCl ₂ · 2H ₂ O (deliquescent)

Further, for example, the solid or powder of cobalt chloride contained in the reagent 5 absorbs water vapor, water, and a solution containing water, and is deliquescent, liquefied, and discolored according to the following reaction formula.
CoCl ₂ (blue) + 2H ₂ O → CoCl ₂ .2H ₂ O (pink or red)

  Further, for example, solid or powder of sodium hydroxide, luminol, an oxidizing agent (for example: potassium permanganate, potassium dichromate), or a catalyst having an iron complex (for example: hemoglobin, hemin) contained in the reagent 5 is in an aqueous solution. The light is emitted according to the following reaction formula.

  The damage monitoring sensor 3 of the present embodiment having the above-described configuration is fixed in the insertion hole 2 shown in FIG. 1B so that the protective film 6 faces the bottom of the insertion hole 2. Then, as shown in FIG. 1D, when the wall thickness 1 of the monitoring target device is reduced to the position of the damage monitoring sensor 3 due to the occurrence of corrosion, cracking, erosion / corrosion, etc., the damage monitoring sensor 3, a solution containing water vapor, aqueous solution and water inside the monitoring target device enters through the protective film 6 through the protective film 6, and the reagent 5 absorbs this and changes its color and emits light. As schematically shown in the circular area in the upper part of FIG. 1D, the light emitted at this time is led out through the monitoring window 7 and can be confirmed from the outside. It can be known that the thinning of the wall 1 of the device has reached a predetermined level, for example, a level that requires maintenance such as replacement.

  As described above, according to this embodiment, the damage monitoring sensor 3 discolors and emits light simply by absorbing water vapor, water, and a solution containing water leaked from the wall 1 of the monitoring target device, and the actual monitoring target. The thinning generated in the wall 1 of the device can be directly detected and notified to the outside, and the safety of the monitored device can be ensured. In addition, electrodes, electrical circuits, measuring instruments, and the like that are indispensable for conventional corrosion sensors can be eliminated, and no erroneous detection due to an electrical failure or the like occurs.

  In addition, it is preferable to make the insertion hole 2 of the minimum necessary size in the wall part 1 according to the thickness of the wall part 1 of a monitoring object apparatus, or a design safety standard. For this reason, it is preferable that the diameter of the charging hole 2 and the diameter of the body 4 of the damage monitoring sensor 3 in the portion inserted into the charging hole 2 are, for example, about 100 μm to 50 cm. Furthermore, the depth of the insertion hole 2 of the corrosion monitoring sensor 3 is set according to the wall thickness 1 of the monitoring target device and the design safety standard.

  Further, as shown in FIG. 3, after the damage monitoring sensor 3 is attached to the insertion hole 2 of the wall 1 of the monitoring target device, the portion 1 of the monitoring target device is in contact with the damage monitoring sensor 3. It is preferable to install the welding seal 8. As a result, it is possible to prevent the damage monitoring sensor 3 from falling off, and to reliably prevent leakage of gas and liquid inside the monitoring target device from the insertion hole 2.

  Further, the protective film 6 for protecting the reagent 5 of the damage monitoring sensor 3 is made of, for example, a carbon fiber having good air permeability or a porous ceramic film. The protective film 6 has a function of facilitating the penetration of moisture into the reagent 5 as shown in FIG. 4A and at the same time preventing the outflow of moisture from the reagent 5 as shown in FIG. 4B. . Further, as shown in FIG. 4A, the protective film 6 has a function of preventing foreign substances having a certain size or more (for example, a diameter of 5 μm or more) from entering the reagent 5.

  Next, an embodiment of damage monitoring by the damage monitoring sensor 3 will be described with reference to FIGS.

  FIG. 5 shows a case in which the damage monitoring sensor 3 is applied to industrial, private, and power generation pipes 10 where corrosion, cracks, erosion and corrosion, etc. occur. In this case, more specifically, for example, a main steam pipe of a power plant, a transport pipe of a chemical plant, an oil or petroleum gas transport pipe, and the like are monitored by the damage monitoring sensor 3.

  FIG. 6 shows a case where the damage monitoring sensor 3 is applied to the casing 21 of the power generation turbine 20 in which corrosion, cracking, erosion / corrosion, etc. occur. In this case, more specifically, for example, the casing 21 of the steam turbine, the gas turbine, and the geothermal turbine of the power plant is the monitoring target of the damage monitoring sensor 3.

  FIG. 7 shows a case where the damage monitoring sensor 3 is applied to a body 31 of an industrial, civilian or power generation heat exchanger 30 where corrosion, cracking, erosion / corrosion, etc. occur. In this case, more specifically, for example, a steam generator, a deaerator, a condenser and the like of the power plant are monitored by the damage monitoring sensor 3.

  FIG. 8 shows a case where the damage monitoring sensor 3 is applied to a pressure vessel 40 for industrial use, private use and power generation in which corrosion, cracking, erosion / corrosion and the like occur. In this case, more specifically, for example, a chemical liquid storage tank, a petroleum storage tank, a nuclear fuel storage tank, or the like of a chemical plant is a monitoring target of the damage monitoring sensor 3.

  As described above, according to the present embodiment, the actual damage state of the monitoring target device is caused by the discoloration / light emission of the reagent filled in the damage monitoring sensor without using an electric circuit and a measuring device. Can be monitored directly. Therefore, it is possible to avoid risks such as electrical circuit maintenance and malfunctions, and to manage the thickness of the monitored device. By inserting a damage monitoring sensor at a specified position, the degree of damage to the monitored device can be accurately determined. Can be monitored. Thereby, the safe driving | operation of the monitoring object apparatus is securable.

The flowchart for demonstrating the damage monitoring method in one Embodiment of this invention. It is a figure which shows typically the structure of the damage monitoring sensor in one Embodiment of this invention, (a) is a bottom view, (b) is a longitudinal cross-sectional view. Sectional drawing which shows typically the attachment state of the damage monitoring sensor in one Embodiment of this invention. Sectional drawing which shows typically the effect | action of the protective film in one Embodiment of this invention. The perspective view which shows typically embodiment which applied this invention to monitoring of piping. Sectional drawing which shows typically embodiment which applied this invention to monitoring of the turbine casing. Sectional drawing which shows typically embodiment which applied this invention to the monitoring of the fuselage | body of a heat exchanger. The side view which shows typically embodiment which applied this invention to the monitoring of a pressure vessel.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wall part of monitoring object device, 2 ... Insertion hole, 3 ... Damage monitoring sensor, 4 ... Body, 5 ... Reagent, 6 ... Protective film, 7 ... Monitoring window, 8 ... Welding Seal 10, piping 20, turbine 21, turbine casing 30, heat exchanger 31, heat exchanger body 40, pressure vessel

Claims (13)

A damage monitoring sensor for monitoring a damage state inside a wall portion separating an inside and an outside where a fluid is contained or distributed in a monitoring target device,
A body formed in a cylindrical shape, the inside of which is a reagent containing portion for containing a reagent;
A reagent housed in the reagent housing section and reacting with the fluid or a substance contained in the fluid to exhibit at least one of discoloration and luminescence; and
A monitoring window provided at the top of the body, for monitoring the state of the reagent in the reagent container;
An opening formed at the bottom of the body and allowing the fluid to enter the reagent container;
A protective film that is provided in the opening and allows the ingress of fluid and protects the reagent;
The protective film is inserted and fixed in an insertion hole provided from the outside in the wall portion so as to face the bottom portion in the insertion hole, and the inside of the wall portion is damaged so that the fluid enters the reagent storage portion. In this case, the damage monitoring sensor is characterized in that damage on the inside of the wall portion can be detected by at least one of discoloration and light emission of the reagent. The damage monitoring sensor according to claim 1,
The fluid includes at least water vapor or water;
The damage monitoring sensor, wherein the reagent contains a solid or powder of calcium chloride or lithium chloride as a substance that absorbs moisture. The damage monitoring sensor according to claim 1,
The fluid includes at least water vapor or water;
A damage monitoring sensor, wherein the reagent contains a solid or powder of cobalt chloride as a substance that changes color by absorbing moisture. The damage monitoring sensor according to claim 1,
The fluid includes at least water vapor or water;
A damage monitoring sensor, wherein the reagent contains a solid or powder of sodium hydroxide, luminol, an oxidizing agent, and a catalyst having an iron complex as a substance that absorbs moisture and emits light. The damage monitoring sensor according to claim 4,
A damage monitoring sensor, wherein the oxidizing agent is at least one of potassium permanganate and potassium dichromate. The damage monitoring sensor according to claim 4 or 5,
A damage monitoring sensor, wherein the catalyst having the iron complex is at least one of hemoglobin and hemin. The damage monitoring sensor according to claim 1,
The damage monitoring sensor, wherein the protective film is made of a carbon fiber having a gas permeability or a porous ceramic film. The damage monitoring sensor according to any one of claims 1 to 7,
The said trunk | drum is comprised from the metal material which has corrosion resistance and heat resistance, and is fixed to the said insertion hole with a screw or welding, The damage monitoring sensor characterized by the above-mentioned. The damage monitoring sensor according to any one of claims 1 to 8,
A damage monitoring sensor, wherein the monitoring window is made of glass or quartz glass having pressure resistance, heat resistance, and corrosion resistance.   A damage monitoring method according to claim 1, wherein the damage monitoring sensor according to claim 1 is provided in a pipe and the damage state of the pipe is monitored.   A damage monitoring method according to claim 1, wherein the damage monitoring sensor according to claim 1 is provided in a turbine casing and a damage state of the turbine casing is monitored.   A damage monitoring method comprising: providing the damage monitoring sensor according to any one of claims 1 to 9 on a body of a heat exchanger, and monitoring a damaged state of the body of the heat exchanger.   A damage monitoring method according to claim 1, wherein the damage monitoring sensor according to claim 1 is provided in a pressure vessel, and a damage state of the pressure vessel is monitored.

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