JPH05264509A - Positioning method for operation and operating apparatus of multitube-type heat exchanger and method and apparatus for position detection - Google Patents

Abstract

PURPOSE:To automatically perform the operation such as the inspection of a heat transfer tube by a method wherein, in a state that one pair of detection elements have been arranged by keeping an interval in a direction perpendicular to the tube axis of the heat transfer tube, they are moved along the direction and a position is detected when outputs of both detection elements become equal. CONSTITUTION:In a multitube-system heat exchanger, many heat transfer tubes 3 whose tube axis is horizontal are installed inside its trunk; end parts of the individual heat transfer tubes 3 are fixed airtightly after tube plates 4 have been inserted. One pair of detection elements 43, 44 which detect edges of the heat transfer tubes 3 and which have been fixed integrally are moved along a direction perpendicular to the tube axis of the many heat transfer tubes 3; the edges of the heat transfer tubes 3 are detected by means of the individual elements 43, 44. Then, a position is detected when individual outputs of both elements 43, 44 become an equal output value. Thereby, an operation at the inside of the heat transfer tubes 3, e.g. a positioning operation for operating use as an operation means to perform an eddy-current flaw detection inspection operation or the like, can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning method and a working apparatus for performing positioning such as eddy current flaw detection of a multi-tube heat exchanger. The present invention also relates to a method and apparatus for detecting the position of a detected object such as a heat transfer tube.

[0002]

2. Description of the Related Art As a vaporizer for vaporizing liquefied gas using seawater, a shell-and-tube heat exchanger, which is also called a shell-and-tube heat exchanger, is used. The number of heat transfer tubes of this multi-tube heat exchanger is, for example, thousands, and the number thereof is large. Conventionally, an operator conducts an eddy-current flaw detection test for such a large number of heat transfer tubes.

[0003]

Such a manual eddy current flaw detection test for a large number of heat transfer tubes is a simple work, requires a lot of labor, and has a large variation in the quality of the test.

An object of the present invention is to provide a positioning method for work such as inspection of a multi-tube heat exchanger, and to provide a working device capable of automatically performing work such as inspection of heat transfer tubes. That is.

Another object of the present invention is to provide a method and apparatus for detecting the position of an object to be detected such as the tube axis of a heat transfer tube.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a pair of integrally fixed detection elements for detecting an end face of a heat transfer tube of a multi-tube heat exchanger are arranged in a direction perpendicular to a tube axis of the heat transfer tube. Positioning for work means for working inside the heat transfer tube by detecting the position when the outputs of both detection elements are equalized by moving along the above direction with the open position. This is a working positioning method for a multi-tube heat exchanger.

Further, the present invention provides a working means for working inside the heat transfer tube of the multi-tube heat exchanger, and a moving direction of the working means in the direction perpendicular to the tube axis of the heat transfer tube in the vicinity of the end surface of the heat transfer tube. And a moving means fixed to the working means, spaced apart in the moving direction, a pair of detection elements for detecting the end face of the heat transfer tube, and in response to each output of both detection elements, each output is And a control means for stopping the moving means when they are equal to each other.

Further, according to the present invention, a pair of integrally fixed detecting elements for respectively detecting the object to be detected are moved along the object to be detected, and during the movement, the outputs of both the detecting elements become equal. A position detecting method characterized by detecting a position.

Further, according to the present invention, a pair of integrally fixed detection elements for respectively detecting the object to be detected, a moving means for moving both of the detection elements along the object to be detected, and an output of each of the detection elements are provided. And a means for detecting a position when the respective outputs become equal to each other, the position detecting device.

[0010]

According to the present invention, a pair of integrally fixed detection elements are moved along a direction perpendicular to the tube axes of a large number of heat transfer tubes of a multi-tube heat exchanger, and each detection element By detecting the end surface of the heat transfer tube and detecting the position when each output of both detection elements has the same output value, work means for performing work inside the heat transfer tube, for example, eddy current flaw detection inspection work, etc. It is possible to carry out work positioning.

According to the present invention, the working means for working inside the heat transfer tube is moved by the moving means in the moving direction perpendicular to the tube axis of the heat transfer tube in the vicinity of the end surface of the heat transfer tube. , By this moving means, a pair of detecting elements are moved together with the working means, each detecting element detects the end surface of the heat transfer tube, and when the respective output values of both detecting elements become equal, the moving means is stopped, In this way, it becomes possible to perform work such as eddy current flaw detection inspection inside the heat transfer tube by the working means.

According to the present invention, the pair of integrally fixed detection elements is moved along the object to be detected in a direction perpendicular to the tube axis of the heat transfer tube, and both the detection elements are moved during the movement. By detecting the position when the outputs of the elements become equal, it becomes possible to detect the tube axis of the heat transfer tube, for example. Such a position detection method and device for an object to be detected is
The present invention can be widely applied not only to the heat transfer tube but also to various other objects to be detected.

[0013]

1 is a sectional view of an embodiment of the present invention,
FIG. 2 is a diagram showing the overall configuration. The shell-and-tube heat exchanger 1 is used to vaporize the liquefied gas with seawater. In this heat exchanger 1, a heat transfer tube 3 having a large number of horizontal tube axes is provided in a body 2, and an end portion of each heat transfer tube 3 is fixed in an airtight manner by inserting a tube plate 4. The heat transfer tube 3 is made of, for example, titanium or copper alloy, and the tube sheet 4 is made of stainless steel.
When the eddy current flaw detection of the heat transfer tube 3 of the multi-tube heat exchanger 1 is regularly performed, the inspection device 5 can automatically perform the automatic inspection of the heat transfer tube 3. To vaporize the liquefied gas, seawater is passed through the heat transfer tube 3
A liquefied gas to be vaporized is supplied to the space 6 formed by the outer peripheral surface of the tube sheet 4 and the tube sheet 4.

An inspection device 5 is attached by a bracket 8 to an outward flange 7 attached to an end portion of the body 2 to which the tube sheet 4 is fixed, at the time of periodic inspection.

FIG. 3 is a front view of the inspection device 5, and FIG. 4 is a sectional view of the inspection device 5. The bracket 8 is fixed to a pair of columns 9 and 10, and these columns 9 and 10
The connecting members 11 and 12 are fixed between 10 and thus the frame body 6 is formed by the support columns 9 and 10 and the connecting members 11 and 12.
1 is configured. Rails 13 and 14 extending in the horizontal x direction are fixed to the connecting members 11 and 12, respectively. The support 15 extends in the vertical y-direction,
It is guided by 14 and is movable in the x direction. The moving body 16 can move up and down along the support body 15 in the y direction.

A motor 17 is provided to move the support 15 in the x direction, and the rope 20 is wound around a pulley 18 driven by the motor 17 and another pulley 19 to support the support 15. The rope 20 which is fixed to and is made endless is driven, and thus the support body 15 can be horizontally reciprocated in the direction of the arrow 21. A motor 22 is attached to the support body 15 so that the moving body 16 can be moved up and down, whereby the pulley 23 is driven. The support 15 is provided with another pulley 24. The moving body 16 is provided with two pulleys 25 and 26. The upper end portion of the cord 27 is fixed to the support body 15, wound around the pulley 25 through the pulley 23, and further wound around the pulley 24 through the pulley 26, and the lower end portion of the cord 27 is fixed to the support body 15.

A right cylindrical sleeve 29 is fixed to the moving body 16 as shown in FIG. This sleeve 29
As shown in FIG. 1, the eddy current flaw detection inspection probe 3 is provided therein.
0 is accommodated and the probe 30 is inserted into the heat transfer tube 3 by the compressed air from the air gun 31. At this time, the cord 33 fixed to the probe 30 is supplied from the winding means 34, and then the winding means 34 is wound. An eddy-current flaw detection test of the heat transfer tube 3 is performed while the sleeve 30 is being wound by the means 34 and being pulled back inside the heat transfer tube 3 to move. The eddy current inspection method is
This is a non-destructive test method utilizing an electromagnetic induction phenomenon, in which a probe 30 is inserted in the heat transfer tube 3 and a coil in which an alternating current is passed is provided in the probe 30, and the coil is transferred by an alternating magnetic field of the coil. Eddy current is generated in the circumferential direction of the heat tube 3,
When the heat transfer tube 3 has defects such as cracks and corrosion, the eddy current changes, and at this time, the impedance of the coil changes and is detected as an electric signal. Looking at the locus of the impedance change of the coil due to the defect of the heat transfer tube 3 with an oscilloscope, an 8-shaped Lissajous waveform is drawn, and the phase angle formed by this horizontal axis and the apex of the 8-shaped Lissajous waveform is
It corresponds to the position of the defect on the inner surface or the outer surface of the heat transfer tube 3 and the depth of the defect.

The movable body 16 is positioned so that the probe 30 can be accurately and automatically inserted into the heat transfer tube 3. The working means 35 for performing the eddy current flaw detection inspection inside the heat transfer tube 3 includes a sleeve 29, a probe 30, an air gun 31,
The rope 33 and the winding means 34 are included.
This working means 35, and thus the moving means 36 for moving the moving body 16 in the xy plane, is the rail 1 for the x direction.
3, 14, pulleys 18 and 19, a belt 20, and a motor 17, and in the y direction, pulleys 23 to 26, a cord 27, a motor 22, and the like. In this way, the sleeve 29 can move in the x direction or the y direction which is the moving direction in the xy plane perpendicular to the tube axis 37 of the heat transfer tube 3 in the vicinity of the end surface 3a of the heat transfer tube 3 (see FIG. 1). You can

In order to detect the position of the sleeve 29 with respect to the heat transfer tube 3, a detecting means 38 is fixed to the end portion of the sleeve 29. FIG. 5 is a front view of the detection means 38. Figure 1
Referring to FIG. 5 and FIG. 5, the detection means 38 includes two sets of a holding body 40 fitted in the sleeve 29 and fixed by bolts 39, and a fixing hole 41 of the holding body 40 fixed by bolts 42. Detection elements 43 and 44 forming a pair of
45 and 46. The holder 40 has an insertion hole 47 through which the probe 30 is inserted. The axes of the detection elements 43 and 44 are parallel to the y direction, and the other pair of detection elements 45 and 46 have the axes parallel to the x direction. The detection elements 43, 44; 45, 46 forming each pair may have the same structure and may be eddy current sensors that detect the end surface 3a of the heat transfer tube 3 and selectively detect a conductor, or Further, it may be a magnetic sensor that detects magnetic permeability, or an optical sensor that includes a combination of a light emitting diode that irradiates the end surface 3a of the heat transfer tube 3 with light and a phototransistor that receives the reflected light. Alternatively, the end face 3a may be detected by other configurations.

FIG. 6 is a front view of a part of the multi-tube heat exchanger 1 showing the end surface 3a of the heat transfer tube 3 and the tube sheet 4. The detecting means 38 moves the moving means 36 near the end surface 3 a of the heat transfer tube 3.
When it is moved in the y direction by the action of
The output level obtained by 44, along with its y-direction position, is shown by line 48. The reference zero level of the output level 48 is shown by a line 49. When the tube axis 37 of the heat transfer tube 3 and the axis line 50 (see FIGS. 1 and 5) of the sleeve 29 are aligned with each other, each detection element 4
The output levels V1 and V2 of 3,44 are equal. In this way, the sleeve 29 is moved in the y direction by the moving means 36,
When the output levels V1 and V2 of the detection elements 43 and 44 become equal (V1 = V2), it can be determined that the axis 37 of the heat transfer tube 3 and the axis 50 of the sleeve 29 match.

This also means that, as shown in FIG.
The same applies when the sleeve 29 and thus the moving body 16 are moved in the x direction by the moving means 36. Figure 8
(1) is a partial front view showing the end surface 3 a of the heat transfer tube 3 and the tube plate 4 of the multi-tube heat exchanger 1, and the detection elements 43 to 46.
Is the tube axis 37 of the heat transfer tube 3 and their detecting elements 43 to 46.
Shows the state in which the axis line 50 of the sleeve 29 to which is fixed coincides. The detection elements 45 and 46 are the sleeve 2
9 and therefore the output level when moving in the x direction together with the moving body 16 is shown by the line 51 in FIG. 8 (2).
When the tube axis 37 of the heat transfer tube 3 and the axis line 50 of the sleeve 29 coincide with each other, the output levels V3 of the detection elements 45 and 46 are V3.
V4 is equal (V3 = V4). Reference numeral 52 in FIG. 8 (2)
Indicates the zero level of the output level of the detection elements 45 and 46.

FIG. 9 is a block diagram showing the electrical construction of the embodiment shown in FIGS. Detection elements 43 to 46
The respective outputs of the above are given to the processing circuit 54 realized by a personal computer or the like. The processing circuit 54 is connected to the memory 55, and the detection result is displayed on the display means 56. The processing circuit 54 is the motor 1 of the moving means 36.
7, 22 and also controls the operation of the air gun 31,
Further, the winding means 34 for pulling back the eddy current flaw detection inspection probe 30 is driven.

The output of the eddy current flaw detection inspection probe 30 is given to the flaw detector 53, the Lissajous waveform corresponding to the defect of the heat transfer tube 3 is displayed by the display means 57, and the recording paper 59 is inspected by the recording means 58 which is a chart recorder. The result is recorded for each heat transfer tube 3 in the direction of its axis 37, in the longitudinal direction of the recording paper 59.

FIG. 10 is a flow chart for explaining the operation of the processing circuit 54 shown in FIG. Pillar 9,
After the frame body 61 composed of 10 and the connecting members 11 and 12 is mounted on the flange 7 of the multi-tube heat exchanger 1 by the bracket 8, the working device 5 is used to eddy current flaw detection of many heat transfer tubes 3. When inspecting, first the sleeve 2 of the working means 35
When positioning the working means 35, and thus the moving body 16, by aligning the axis 50 of 9 with the axis 37 of the heat transfer tube 3 to be inspected, the process moves from step n1 to step n2 in FIG. 22 to drive the sleeve 29 of the working means 35 and thus the moving body 16
Direction, move to step n3, and detect elements 43, 4
It is detected whether the outputs V1 and V2 of 4 have become equal. When it is determined that the output values V1 and V2 of the detection elements 43 and 44 are equal, the process proceeds to the next step n4, the motor 22 is stopped, and the movement of the sleeve 29 in the y direction is stopped. In the next step n5, the motor 17 is driven to move the sleeve 29 of the working means 35, and thus the moving body 16, to x.
Direction, the output levels V3 and V4 of the detection elements 45 and 46 at this time are judged to be equal in step n6. When the outputs V3 and V4 of the detection elements 45 and 46 become equal, the motor 17 is stopped in step n7, and the movement of the sleeve 29 in the x direction is stopped.
At 8, a series of operations is stopped. At this time, the sleeve 29
The axis line 50 of is exactly aligned with the tube axis 37 of the heat transfer tube 3 to be inspected. After that, the processing means 54 operates the air gun 31 to shoot the eddy current flaw detection inspection probe 30 into the tube 3, then drives the reel 34, winds the cord 33, and pulls the probe 30 back in the heat transfer tube 3. At this time, an eddy current flaw detection test for defects in the heat transfer tube 3 is performed by the flaw detector 53 and the recording means 58.

In the above embodiment, the detection elements 43 to 46 are used.
Is the output level V1, near the outside in the radial direction of the heat transfer tube 3.
V2 (see FIG. 7) and V3, V4 (see FIG. 8 (2))
Are arranged to detect whether the two are equal, but as shown in FIG. 11 as another embodiment of the present invention, the detecting elements 43 to 46 are moved during the positioning operation,
Move inward in the radial direction toward the axis 50 of the sleeve 29,
It may be possible to detect whether or not the output levels V11 and V21 of the detection elements 43 and 44 in the vicinity of the inner peripheral surface of the heat transfer tube 3 are equal, and this is the same for the detection elements 45 and 46. In this embodiment, when the probe 30 is inserted into the heat transfer tube 3, the detection elements 43 to 46 have a structure that can be retracted radially outward so as not to hinder the insertion movement of the probe 30. ..

FIG. 12 is a perspective view of a part of still another embodiment of the present invention. This embodiment is similar to the previous embodiment, and corresponding parts bear the same reference numerals. In this embodiment, when the moving body 16 moves perpendicularly to the axis 37 of the heat transfer tube 3, the worker moves the supporting body 15 along the rails 13 and 14 in the x direction, and moves the moving body 16 to the supporting body 15.
Along the y direction. The operator uses the detection elements 43 to 4 which are provided in the detection means 38 and are the same as those in the above-described embodiment.
Based on the output of 6, it is possible to know whether the axis line 50 of the sleeve 29 and the axis line 37 of one heat transfer tube 3 to be inspected are exactly aligned.

[0027]

As described above, according to the present invention, a pair of detection elements for detecting the end surface of the heat transfer tube are integrally fixed,
By moving in a direction perpendicular to the tube axis of the heat transfer tube and detecting the position when the output values of both detection elements are equal,
Since it is possible to perform the work positioning for the working means that performs the work inside the heat transfer tube, it is possible to automatically position the working means.

Further, according to the present invention, the working means can be moved by the moving means in the direction of movement close to the end surface of the heat transfer tube in the direction perpendicular to the tube axis of the heat transfer tube to perform work.
A pair of detection elements are arranged and attached to the working means at intervals in the moving direction, and the moving means is stopped when the values of the outputs of the detection elements become equal to each other. It becomes possible to automatically perform the work by the working means, such as inserting the eddy current flaw detection inspection head into the inside of the heat transfer tube.

According to the present invention, an object to be detected such as an end face of a heat transfer tube is detected by a pair of detection elements fixed to each other, and a position where the outputs of both detection elements are equal is detected. This makes it possible to detect a position such as the tube axis of the heat transfer tube. The present invention can be widely applied not only to the heat transfer tube but also to other objects to be detected.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view around a detecting means 38 according to an embodiment of the present invention.

FIG. 2 is a perspective view of the entire working device 5 according to the embodiment of the present invention.

FIG. 3 is a front view of the working device 5.

FIG. 4 is a cross-sectional view of a working device 5.

5 is a front view of the inspection means 38. FIG.

FIG. 6 is a partial front view showing an end surface 3a of the heat transfer tube 3 and a tube sheet 4.

FIG. 7 is a diagram showing outputs of a heat transfer tube 3 and detection elements 43 and 44.

FIG. 8 is a diagram showing heat transfer tubes 3 and outputs of detection elements 45 and 46.

9 is a block diagram showing an electrical configuration of the embodiment shown in FIGS. 1 to 8. FIG.

10 is a flow chart for explaining the operation of the processing circuit shown in FIG.

FIG. 11 is a diagram showing another embodiment of the present invention.

FIG. 12 is a perspective view of still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-tube heat exchanger 2 Body 3 Heat transfer tube 3a End surface 4 Tube plate 5 Inspection device 9,10 Support 11,12 Connecting member 13,14 Rail 15 Support 16 Moving body 17,22 Motor 29 Sleeve 30 Eddy current flaw detection probe 33 rope 34 winding means 35 working means 36 moving means 38 detecting means 43, 44; 45, 46 detecting element 53 flaw detector 54 processing circuit 55 memory 56, 57 display means 58 recording means 59 recording paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Futoku Sato, 1-2-2 Hirano-cho, Chuo-ku, Osaka City Osaka Gas Co., Ltd.

Claims (4)

[Claims] 1. A pair of integrally fixed detection elements for detecting an end face of a heat transfer tube of a multi-tube heat exchanger are arranged at intervals in a direction perpendicular to a tube axis of the heat transfer tube, A multi-tube heat exchanger that moves along the above direction, detects the position when the outputs of both detection elements become equal, and performs work positioning for work means that works inside the heat transfer tube. Positioning method for work. 2. A working means for working inside the heat transfer tube of the multi-tube heat exchanger, and the working means is moved in the moving direction perpendicular to the tube axis of the heat transfer tube in the vicinity of the end surface of the heat transfer tube. A pair of detection elements that are fixed to the moving means and the working means and are spaced from each other in the moving direction, and detect the end face of the heat transfer tube, and respond to each output of both detection elements, and each output becomes equal. And a control means for stopping the moving means, the working apparatus for the multi-tube heat exchanger. 3. A pair of integrally fixed detection elements for respectively detecting an object to be detected are moved along the object to be detected, and a position where the outputs of both the elements are equalized is detected during the movement. A position detecting method characterized by: 4. A pair of integrally fixed detection elements for respectively detecting an object to be detected, moving means for moving both of the detection elements along the object to be detected, and responding to respective outputs of both the detection elements, A position detecting device for detecting a position when the respective outputs become equal to each other.