JP6830764B2 - Contact type inspection device and contact type inspection method - Google Patents

Description

The contact-type inspection device and the contact-type inspection method according to the present application relate to an inspection technique in which a steam trap, a valve, or the like provided in a piping system is targeted for inspection, and the inspection target is inspected by contacting the detection unit with the inspection target. ..

Industrial plants may be equipped with a piping system that transfers steam generated by the boiler to the supply destination at high temperature and high pressure. When steam is liquefied in this pipe, drain (condensed water of steam) stays and the space for steam transfer is reduced, resulting in a decrease in steam transfer efficiency.

In order to avoid such a situation, a large number of steam traps are provided everywhere in the piping system. For example, in a float type steam trap, when the amount of drain water inside due to liquefaction reaches a certain level, the built-in float floats to open the outlet of the steam trap and automatically discharges the drain to the outside of the pipe. It has a structure to do.

By the way, if the steam trap malfunctions, proper steam transfer is hindered, and efficient operation of the industrial plant cannot be ensured. For this reason, a technique for inspecting the operating state of a steam trap is emphasized.

There are two cases of malfunction of the steam trap: poor discharge and poor sealing. Drainage failure occurs when drainage cannot be discharged from the discharge port due to foreign matter being mixed in, and when discharge failure occurs, excessive drainage stays in the pipe. On the other hand, poor sealing is caused by a gap between the outlet and the float, which should be sealed due to wear or deformation of the float. If the outlet cannot be sealed, steam will be generated from here. Leakage occurs, leading to a decrease in steam transfer efficiency.

When a discharge defect occurs in the steam trap, the surface temperature of the steam trap itself decreases due to the retention of drainage, so that the discharge defect can be detected by measuring the surface temperature of the steam trap. On the other hand, when the steam trap has a poor sealing, a leaking sound is generated due to the leakage of steam and the steam trap vibrates. Therefore, the poor sealing can be detected by measuring the vibration of the surface of the steam trap. ..

Here, when inspecting a steam trap, it is desirable to detect both discharge failure and sealing failure at the same time from the viewpoint of inspection efficiency. Therefore, an inspection device has been proposed in which a temperature sensor and a vibration sensor are provided at the tip of the probe, and both are brought into contact with the measurement point to be inspected at the same time.

Then, in order to perform an accurate inspection, it is necessary to position the probe perpendicularly to the target surface and bring it into contact with the target surface. In this regard, since the sensor part of the probe is sharply configured to correspond to various steam trap shapes and various measurement points, the inspector holds the probe vertically by hand without relying on a vertical guide member or the like. Must be inspected.

As such an inspection device, there is a technique disclosed in the patent document described later. This tester is equipped with a spirit level at the rear end of the probe. When the probe is tilted, the position of the bubble in the bubble tube of the spirit level moves, so that the inspector can recognize the tilt by visually recognizing the deviation of the positional relationship between the bubble and the reference line. The inspector who recognizes the tilt corrects the probe vertically and continues the inspection.

Japanese Patent Application Laid-Open No. 2008-170389

However, in the technique disclosed in the above-mentioned patent document, it is necessary to confirm the verticality of the probe while looking into the spirit level from above, and there is a problem that the inspection efficiency is poor. In particular, when inspecting steam traps for intricately arranged pipes, the spirit level may not be visible.

Further, for example, when inspecting a slope portion as a measurement point instead of the horizontal plane of the steam trap, there is a problem that the vertical to the target surface cannot be confirmed by the spirit level.

Therefore, the contact-type inspection device and the contact-type inspection method according to the present application have a problem of solving these problems, and the contact-type inspection device and the contact-type inspection method capable of easily and surely grasping the inclination of the inspection device. For the purpose of providing.

The contact type inspection device according to the present application is
Targeting objects that repeatedly rise and fall in temperature,
Temperature detector that brings the object into contact with the specified proper contact condition,
In the contact type inspection device equipped with
A temperature storage unit that stores the maximum temperature determined based on the measured temperature of the object detected by the temperature detection unit,

A control unit that calculates a lowering reference temperature that is lower than the maximum temperature according to a predetermined calculation rule, and outputs an inappropriate signal when the measured temperature of the object detected by the temperature detection unit falls below the lowering reference temperature.
Notification processing unit that receives an inappropriate signal from the control unit and performs notification processing,
It is characterized by having.
In addition, the contact type inspection method according to the present application is
In a contact-type inspection method in which an object whose temperature repeatedly rises and falls is targeted for inspection and the temperature detection unit is brought into contact with the object with a predetermined proper contact state.
The maximum temperature determined based on the measured temperature of the object detected by the temperature detector is stored.

According to a predetermined calculation rule, the lowering reference temperature of a value lower than the maximum temperature is calculated, and when the measured temperature of the object detected by the temperature detector falls below the lowering reference temperature, an inappropriate signal is output.
Receives an inappropriate signal and performs notification processing,
It is characterized by that.

In the contact-type inspection device and the contact-type inspection method according to the present application, when the measurement temperature of the object detected by the temperature detection unit falls below the lowering reference temperature, an inappropriate signal is output and notification processing is performed. Here, if the inspection device is tilted during the inspection and an improper contact state occurs, the contact between the temperature detection unit and the object becomes insufficient, and the measurement temperature drops significantly.

Therefore, the inspector can easily and surely grasp the inclination of the inspector by the notification process performed when the temperature falls below the lowering reference temperature. It should be noted that the repeated rise and fall of the temperature of the object obtained under the proper contact state is regarded as a temperature change between the maximum temperature and the fall reference temperature, so that an inappropriate signal is not output. Therefore, the inclination of the inspection device can be accurately grasped.

It is a figure which shows the inspection apparatus as the 1st Embodiment of the contact type inspection apparatus and the contact type inspection method which concerns on this application, (A) is the figure which shows the main body and probe which constitute inspection apparatus, (B) is the figure of the probe. An enlarged side view of the vicinity of the tip portion, (C) is a front view of the tip portion of the probe viewed from the direction of arrow C. It is a functional block diagram of the electric circuit of the inspection equipment shown in FIG. It is a figure which shows the state which the tip part of the probe shown in FIG. 1 is in contact with the measurement point of an object, (A) is the figure which shows the state which the probe is in contact in the vertical state, and (B) is the state where the probe is tilted It is a figure which shows the contact state in the state of being in contact with each other. It is a flowchart of the process executed by the control part of the inspection equipment shown in FIG. It is a figure which shows the change of the measurement temperature measured by the inspection apparatus shown in FIG.

[Terminology in the embodiment]
The main terms shown in the embodiments correspond to the following components of the contact type inspection device and the contact type inspection method according to the present application, respectively.
Control unit 6 ... Control unit Memory 8 ... Temperature storage unit Vibration sensor 20 (Detection needle 2) ... Vibration detection unit Temperature sensor 40 (Thermocouple 4) ... Temperature detection unit Error sound generation unit 59 ... Notification processing unit Vertical state ... Proper contact State, vertical contact state Steam trap ... Object
MAX temperature ... Maximum temperature Allowable temperature ... Decrease reference temperature Error signal ... Inappropriate signal
15 seconds ... Detection elapsed time
90% of MAX temperature ... Calculation rule [1st embodiment]

The first embodiment of the contact type inspection device and the contact type inspection method according to the present application will be described with reference to the drawings. As shown in FIG. 1 (A), the inspection device according to the present embodiment includes a main body 50 and a probe 10. The plug 52 of the cable 53 is attached to the connection portion 51 of the main body 50, and the main body 50 and the probe 10 are connected via the cable 53. A display screen 55 is provided on the main body 50, and various information is displayed.

A protective tube 11 is provided at the probe tip 10a of the probe 10, and the detection needle tip 2a of the detection needle 2 projects from the protective tube 11 as shown in FIG. 1 (B). The detection needle 2 is urged in the protruding direction by a spring portion (not shown) in the probe 10, and a piezoelectric element (not shown) is connected to the rear end portion of the detection needle 2 in the probe 10. .. When the inspection is performed using the inspection device according to the present embodiment, the probe tip 10a is pressed against the measurement point of the steam trap to be inspected, and the detection needle tip 2a is sufficiently buried in the protective tube 11. As a result, the vibration of the measurement point is transmitted to the detection needle 2, causes a voltage fluctuation in the piezoelectric element connected to the rear end of the detection needle 2, and an electric signal representing the vibration is output. These detection needles 2, piezoelectric elements, etc. constitute the detection sensor.

Further, the thermocouple 4 of the temperature sensor slightly protrudes from the protective tube 11 of the probe tip 10a and is fixedly provided. As shown in FIG. 1 (C), the above-mentioned detection needle tip 2a protrudes from the central hole of the thermocouple 4. The thermocouple 4 responds to the temperature at the measurement point and outputs an electrical signal indicating the temperature.

Next, a functional block diagram (FIG. 2) of the electric circuit of the inspection device according to the present embodiment will be described. An electric signal representing the vibration of the measurement point is output from the vibration sensor 20 composed of the detection needle 2, the piezoelectric element, and the like, amplified by the amplifier 21, and given to the control unit 6. Further, the temperature sensor 40 having the thermocouple 4 outputs an electric signal indicating the temperature of the measurement point, which is amplified by the amplifier 41 and given to the control unit 6.

The control unit 6 executes a predetermined process while recording data in the memory 8 and updating the data according to the stored program. Then, when it is determined that an error has been detected, the control unit 6 gives a signal to the error sound generating unit 59 and the display screen 55 to generate an error sound and displays the error on the display screen 55. Further, on the display screen 55, various inspection information corresponding to the signal given from the control unit 6 is displayed. In this embodiment, the functions of the control unit 6, the memory 8, the display screen 55, and the error sound generating unit 59 shown in FIG. 2 are provided in the main body 50 (FIG. 1 (A)).

Subsequently, the operation when the inspector inspects the steam trap provided in the pipe by using the inspection device in the present embodiment will be described. In the steam trap, when drainage occurs or stays in the pipe, the built-in float floats and opens the discharge port, and the drain is automatically discharged to the outside of the pipe. After discharging, the float returns to its original state and the discharge port is closed and sealed. This discharge is performed once every few seconds, and discharge and sealing are repeated.

This steam trap may malfunction, and there are two cases of this malfunction: poor discharge and poor sealing. When a discharge defect occurs, the surface temperature of the steam trap itself decreases due to the retention of the drain, so that the discharge defect can be detected by detecting the surface temperature of the steam trap (for example, the inlet side). On the other hand, when the steam trap has a poor sealing, a leaking sound is generated due to the leakage of steam and the surface of the steam trap vibrates. Therefore, the poor sealing is detected by detecting the vibration peculiar to the leaking sound of steam. It can be detected.

When inspecting a steam trap, the inspector holds the probe 10 and presses the probe tip 10a against the measurement point 60a on the surface 60 of the steam trap as shown in FIG. As described above, since the detection needle tip 2a and the thermocouple 4 protrude from the probe tip 10a, it is possible to detect the temperature and vibration at the measurement point 60a and simultaneously inspect the steam trap discharge failure and sealing failure. it can.

In order to perform proper detection, the inspector needs to position the probe 10 vertically and make contact with it, as shown in FIG. 3 (A). Here, the inspection of poor sealing cannot be performed unless the leakage sound is detected when the float in the steam trap is not in the open position where it is floating but in the position where the outlet is closed. Then, considering that the float is discharged once every few seconds, the vertical state of the probe 10 shown in FIG. 3 (A) is maintained for at least 15 seconds in order to obtain a reliable inspection result. There is a need.

However, since the vertical state of the probe 10 is held and maintained by the inspector, the probe 10 may be tilted as shown in FIG. 3 (B). In this regard, at the start of the inspection, the inspector usually contacts the measurement point 60a with great care so that the probe 10 is positioned vertically, so that the flowb 10 is not tilted from the beginning. , Gradually tilts in 15 seconds.

In particular, when the inspection target is a steam trap provided on a complicated pipe or a steam trap provided at a position where sufficient inspection space cannot be secured, the inspector presses the probe 10 against the measurement point 60a in an unreasonable posture. It can be difficult to stay vertical for 15 seconds.

If the probe 10 is tilted, the detection needle 2 is not sufficiently buried and vibration at the measurement point 60a cannot be detected properly. Further, when the probe 10 is tilted, the thermocouple 4 does not sufficiently contact the surface of the measurement point 60a, and the temperature cannot be detected properly. In the present embodiment, by grasping the state of the decrease in the measurement temperature, it is attempted to identify that the probe 10 is tilted and display an error.

FIG. 4 is a flowchart of a processing program performed by the control unit 6 according to the present embodiment. The content of the process will be specifically described based on this flowchart. When the probe tip 10a of the probe 10 is pressed against the measurement point 60a and the vibration detection needle 2 is buried, the control unit 6 recognizes the start of the inspection and activates the timer to start counting for 15 seconds (step S2). Then, the vibration is measured by the vibration sensor 20 (step S4).

Next, the control unit 6 measures the temperature by the temperature sensor 20 (step S6), and determines whether the measured measured temperature is equal to or lower than the MAX temperature stored in the memory 8 (step S8). Since "0" is stored as the initial MAX temperature, the process proceeds from step S8 to step S16, the measured temperature is stored in the memory 8 as the MAX temperature, and the process returns to step S4 via step S14 to repeat the process.

FIG. 5 is a graph showing the change in the measured temperature by the curve L1. The measurement temperature at the measurement point of the steam trap has risen from the initial measurement temperature v1, and during this period, the processes from step S8 to step S16 are repeatedly executed to continuously update the MAX temperature. Line L2 in Fig. 5 shows the MAX temperature stored and updated.

Then, when the measurement temperature changes from rising to falling, the measurement temperature becomes equal to or lower than the MAX temperature, so the process proceeds from step S8 to step S10. In step S10, the control unit 6 calculates a value of 90% of the MAX temperature as the allowable temperature, and determines whether or not the measured temperature is equal to or lower than this allowable temperature. Line L3 in Fig. 5 shows the allowable temperature.

When the probe 10 is maintained in the vertical state shown in Fig. 3 (A) and the steam trap to be inspected has neither discharge failure nor sealing failure, the measurement temperature is the maximum temperature and the allowable temperature. Repeat ascending and descending within the range. That is, as described above, the steam trap is repeatedly discharged and sealed. When the drain is discharged, the steam trap is filled with high-temperature steam and the surface temperature rises, and the drain is gradually retained due to the sealing of the discharge port. Although the surface temperature of the steam trap drops, it has been confirmed by experiments and experience that the rise and fall of the surface temperature falls within the allowable temperature range from the MAX temperature.

The surface temperature of the steam trap may rise and fall repeatedly as shown in Fig. 5 according to the discharge and sealing performed by the steam trap. In this case, since the measurement temperature exceeds the MAX temperature stored in the memory 8, the MAX temperature is updated in step S16, and the permissible temperature changes accordingly.

Here, it is assumed that the probe 10 held by the inspector is tilted as shown in FIG. 3 (B). In this case, the contact area of the thermocouple 4 with respect to the measurement point 60a is reduced, so that the measurement temperature is significantly lowered. Then, when the measured temperature becomes equal to or lower than the allowable temperature, the control unit 6 proceeds from step S10 to step S12 to perform error processing. In the error processing, for example, a signal is given to the error sound generating unit 59 and the display screen 55 to generate an error sound, and an error is displayed on the display screen 55. The inspector recognizes that the probe 10 is tilted due to this error sound or the like, returns the probe 10 vertically, and continues the inspection. At this time, the 15-second count started in step S2 may be reset.

If the steam trap to be inspected has a discharge failure, the surface temperature of the steam trap will be significantly lowered due to the excessive drain staying for a long time, and it will be below the discharge failure reference temperature v0 in Fig. 5. Become. Therefore, when a temperature equal to or lower than the discharge failure reference temperature v0 is measured in step S6 of FIG. 4, the control unit 6 generates a discharge failure detection sound and displays the discharge failure detection display on the display screen 55. If the steam trap has a defective discharge, maintenance work such as replacement of the steam trap is required, so the inspector immediately ends the inspection for this steam trap.

In addition, when the steam trap to be inspected has a sealing defect, the vibration inherent in the steam leakage sound is measured in step S4, so the control unit 6 generates a sealing defect detection sound and displays the display screen. A sealing defect detection display is displayed on 55. In this case as well, maintenance work such as replacement of the steam trap is required, so the inspector immediately ends the inspection for this steam trap.
[Other embodiments, etc.]

In the above-described embodiment, the inspection device in which the main body 50 and the probe 10 are connected via the cable 53 is shown, but the inspection device is an integrated inspection device in which the function of the main body and the function of the probe are integrated. The configuration of the present application may be applied. Further, although the allowable temperature is calculated using the ratio of 90% of the MAX temperature as the calculation rule, different ratios can be adopted, and different calculation methods may be used as long as an appropriate lowering reference temperature can be calculated.

Further, in the above-described embodiment, the MAX temperature is updated when the measured temperature exceeds the stored MAX temperature, but the measured temperature and the immediately preceding measurement are measured regardless of the stored MAX temperature. The temperature may be compared and the immediately preceding measured temperature when the measured temperature falls below the immediately preceding measured temperature, that is, when the temperature changes from rising to falling, may be updated as the MAX temperature.

Further, in the above-described embodiment, 15 seconds are counted from the start of the inspection regardless of the time when the error sound is generated, but the same time as the time when the error sound is generated is added and counted, and the inspection time is counted. Can be extended to ensure proper inspection.

The steam trap shown in the above-described embodiment repeatedly raises and lowers the temperature by repeatedly discharging the drain, but the inspection target of the contact-type inspection device and the contact-type inspection method according to the present application periodically raises the temperature. And, not limited to the thing that repeats the temperature drop, the thing that may cause some temperature change is also included as the thing that repeats the temperature rise and fall.

2: Vibration detection needle 2a: Detection needle tip 4: Thermocouple 6: Control unit 8: Memory
10: Probe 10a: Probe tip 20: Vibration sensor 40: Temperature sensor
59: Error sound generator

Claims (3)

Targeting objects that repeatedly rise and fall in temperature,
A temperature detecting section and the vibration detecting unit provided on the probe, in order to ensure proper inspection, during the predetermined detection time elapsed, normal contact the probe is positioned perpendicular to the plane of said object temperature detecting portion and the vibration detecting unit is brought into contact with the object with the status,
In the contact type inspection device equipped with
Temperature storage unit for storing a maximum temperature of the temperature detecting unit is determined based on the measured temperature of the object to be detected,
According to a predetermined calculation rule to calculate the falling reference temperature value lower than the maximum temperature, measured temperature of the object to the temperature detection unit detects outputs the improper signal when below the descending reference temperature Control unit,
Receiving said improper signals from the control unit, notification processing unit that performs a notification process,
A contact-type inspection device characterized by being equipped with. In the contact type inspection device according to claim 1,
Updating the maximum temperature on the basis of the measured temperature of the object to the temperature detection unit detects,
A contact type inspection device characterized by the fact that. The object of repeating the increase and decrease in temperature and inspected, with vertical contact probe is positioned perpendicular to the plane of the test object, the contact type contacting a temperature detecting element placed in the probe to the object In the inspection method
Temperature storage unit may store the maximum temperature determined based on the measured temperature of the object to the temperature detection unit detects,
Control unit, according to a predetermined calculation rule to calculate the falling reference temperature value lower than the maximum temperature, measured temperature of the object to the temperature detection unit detects is improper when below the descending reference temperature Output the signal,
Notification processing unit performs a notification process receiving the improper signal,
A contact-type inspection method characterized in that.

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