JP2008076180A - Expanded pipe confirmation and inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expanded pipe confirmation and inspection device having an expanded pipe inspection means for individually detecting the joining state of the heat transfer pipe expanded to be joined to a tube plate and a heat transfer pipe position measuring means for measuring the position of the inspected heat transfer pipe. <P>SOLUTION: The expanded pipe confirmation and inspection device has the expanded pipe inspection means 14 for inspecting the joining of the tube plate 11 and a heat transfer pipe 12 by an eddy current sensor 13 and the heat transfer pipe position measuring means 15 for measuring the position of the heat transfer pipe 12. The heat transfer pipe position measuring means 15 has the first ultrasonic transmitter 26 attached to the insertion jig 16 of the eddy current sensor 13, the first, and second ultrasonic receivers 28 and 29 arranged on the tube plate 11, the second and third ultrasonic transmitters 38 and 39 arranged in the vicinity of the tube plate 11 and an insertion jig position operation part 40 for calculating the propagation time of an ultrasonic pulse to the first and second ultrasonic receivers 28 and 29 from the first ultrasonic transmitter 26 to calculate the position of the insertion jig 16 on the tube plate 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention measures the position of a heat transfer tube inspected by a tube expansion inspection means having an eddy current sensor that individually detects the joining state of a large number of heat transfer tubes that are expanded and bonded to a tube plate of a heat exchanger, and the tube expansion inspection means. The present invention relates to a tube expansion confirmation inspection apparatus having a heat transfer tube positioning means.

In the multi-tube heat exchanger, the heat transfer tube and the tube plate are expanded and joined for each heat transfer tube. For this reason, it is not clear whether the heat transfer tube and the unbonded heat transfer tube have been expanded when the heat transfer tube and the tube plate are expanded, or leakage of the heat transfer tube may occur. there is a possibility. Therefore, when pipe expansion is performed between the heat transfer tube and the tube sheet, the completion data is input every time the pipe expansion is completed, and it is combined with the heat transfer tube arrangement data obtained in advance and joined in the heat transfer tube arrangement diagram. Has been proposed that can display the position of the heat transfer tube that has been completed and can easily distinguish between a heat transfer tube that has been joined and an unjoined heat transfer tube, and can also prevent the occurrence of joint leakage (for example, , See Patent Document 1).

JP 2003-340534 A

However, after installation of a multi-tube heat exchanger, when conducting inspections of expanded joints during periodic inspections or when repairing multi-tube heat exchangers, the heat transfer tubes will be individually inspected on site, During the inspection, there is a high possibility that the distinction between the heat transfer tubes that have been inspected and unexamined heat transfer tubes will be unclear, or that there will be an inspection leak in the heat transfer tubes. This causes a problem of deterioration.

The present invention has been made in view of such circumstances, and is inspected by a pipe expansion inspection means including a vortex sensor for individually detecting the joining state of a large number of heat transfer tubes that are pipe expansion bonded to a tube plate of a heat exchanger, and a pipe expansion inspection means. It is an object of the present invention to provide a pipe expansion confirmation inspection device that has a heat transfer tube positioning means for measuring the position of the heat transfer tube, and prevents the inspection leakage and improves the reliability of the inspection.

The pipe expansion confirmation inspection apparatus according to the present invention that meets the above-described object is provided with a pipe expansion inspection means including an eddy current sensor that individually inspects the joining state of a large number of heat transfer tubes that are piped and joined to a tube plate of a heat exchanger, and the pipe expansion inspection means. A heat transfer tube positioning means for measuring the position of the heat transfer tube inspected by the pipe expansion confirmation inspection device,
The heat transfer tube positioning means is a part of the tube expansion inspection means, and is attached to an insertion jig that supports the eddy current sensor inserted into the heat transfer pipe, and transmits an ultrasonic pulse around the insertion jig. A first ultrasonic transmitter;
First and second receiving ultrasonic pulses transmitted from the first ultrasonic transmitter are arranged with a gap at a predetermined position on the tube plate or on a plane extending from the tube plate. Two ultrasonic receivers;
A second ultrasonic transmitter provided in the vicinity of the tube sheet;
Third and fourth ultrasonic receivers arranged with a gap in the vicinity of the tube plate and receiving ultrasonic pulses transmitted from the second ultrasonic transmitter;
Propagation times t ₁ and t ₂ required for the ultrasonic pulse transmitted from the first ultrasonic transmitter to reach the first and second ultrasonic receivers are respectively determined and stored in advance. An insertion jig position calculation unit that calculates and stores a planar position of the insertion jig on the tube plate from the ultrasonic wave propagation velocity in the vicinity of the tube plate and the propagation times t ₁ and t ₂ ;
In addition, the insertion jig position calculation unit has a propagation time t ₃ required for the ultrasonic pulse transmitted from the second ultrasonic transmitter to reach the third and fourth ultrasonic receivers, From the measurement of t _4, the presence or absence of a change in the ultrasonic propagation velocity near the tube plate is confirmed. If the ultrasonic propagation velocity near the tube plate changes, a new ultrasonic propagation velocity near the tube plate is obtained and stored. There is provided a sound speed corrector for updating the ultrasonic propagation velocity near the tube plate to a new ultrasonic propagation velocity near the tube plate.

In the tube expansion confirmation inspection device according to the present invention, it is preferable that an omnidirectional microphone is used for the first and second ultrasonic receivers.

In the pipe expansion confirmation inspection apparatus according to the present invention, the sound receiving surfaces of the omnidirectional microphones are tilted inward by 40 degrees or more and 50 degrees or less with respect to a straight line perpendicular to a central connection line connecting the centers of the sound receiving faces. Are preferably arranged.

In the pipe expansion confirmation inspection apparatus according to claims 1 to 3, when the heat transfer tubes are sequentially inspected by the pipe expansion inspection means, the planar position of the insertion jig on the tube plate is calculated and stored by the heat transfer pipe positioning means. Therefore, it is possible to sequentially store the heat transfer tubes inspected by the tube expansion inspection means, and easily distinguish between heat transfer tubes that have been inspected and uninspected heat transfer tubes according to the progress of the tube expansion inspection. Is also possible. As a result, it is possible to prevent the heat transfer tube from being inspected and improve the reliability of the inspection work. Also, check whether there is a change in the ultrasonic propagation velocity near the tube plate, and if the ultrasonic propagation velocity near the tube plate changes, obtain a new ultrasonic propagation velocity and calculate the plane on the tube plate of the insertion jig. Since the target position is calculated, the planar position of the insertion jig on the tube plate can be accurately obtained even if the ultrasonic wave propagation speed changes due to changes in temperature and humidity during the inspection.

In particular, in the tube expansion confirmation inspection device according to claim 2, since the omnidirectional microphone is used for the first and second ultrasonic receivers, the first and second ultrasonic transmitters are moved along with the movement of the first ultrasonic transmitter. Even if the incident angle of the ultrasonic pulse incident on each of the two ultrasonic receivers greatly fluctuates, the ultrasonic pulse transmitted from the first ultrasonic transmitter can be reliably received. . As a result, the first ultrasonic transmitter and the first and second ultrasonic receivers can be arranged close to each other. In addition, the rising edge of the received signal of the ultrasonic pulse becomes sharp, the threshold level when detecting the received signal can be set high, and the influence of noise due to external factors such as air flow is eliminated and reliably The first wave can be detected. As a result, ultrasonic pulses propagating in the air can be received with high sensitivity, and the distance between the first ultrasonic transmitter and the first and second ultrasonic receivers can be increased. In addition, the planar position of the insertion jig on the tube sheet can be accurately obtained while moving the insertion jig over a wide range on the tube sheet. On the other hand, when the region where the first ultrasonic transmitter is moved is constant, the first and second ultrasonic receivers are arranged close to the moving region of the first ultrasonic transmitter (compact) ), The ultrasonic pulse from the first ultrasonic transmitter can be accurately detected, and the planar position of the insertion jig on the tube plate can be calculated from a narrow tube plate to a wide tube plate. it can.

In the pipe expansion confirmation inspection apparatus according to claim 3, the sound receiving surfaces of the omnidirectional microphones are inclined inward by 40 degrees or more and 50 degrees or less with respect to a straight line perpendicular to a central connection line connecting the centers of the sound receiving surfaces. Even if the first and second ultrasonic receivers are fixed on the tube plate, the ultrasonic pulse from the first ultrasonic transmitter that moves on the tube plate together with the insertion jig, It can be received reliably.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a block diagram of a tube expansion confirmation inspection apparatus according to an embodiment of the present invention, and FIG. 2 is a receiver holder for attaching first and second ultrasonic receivers used in the tube expansion confirmation inspection apparatus. FIG. 3 is an explanatory diagram of an ultrasonic transmitter / receiver mounting base for mounting the second ultrasonic transmitter and the third and fourth ultrasonic receivers used in the pipe expansion confirmation inspection apparatus, and FIG. 4 is the pipe expansion confirmation. 5 is a block diagram of a data processor of the inspection apparatus, FIGS. 5A to 5C are explanatory diagrams of how to use the expansion confirmation inspection apparatus, and FIG. 6A is an insertion jig position calculation unit of the expansion confirmation inspection apparatus. FIG. 5B is a diagram illustrating the processing contents in FIG. 5B, and a display showing the position of the first ultrasonic transmitter on the tube plate and the status of the ultrasonic pulses received by the first and second ultrasonic receivers, respectively. Fig. 7 is a table showing the pipe expansion inspection status by the pipe expansion confirmation inspection device. Vessels is an explanatory view of a screen.

As shown in FIG. 1, a tube expansion confirmation inspection apparatus 10 according to an embodiment of the present invention is a joint of a large number of heat transfer tubes 12 (see FIG. 5A) expanded and joined to a tube plate 11 of a heat exchanger. It has the pipe expansion inspection means 14 provided with the eddy current sensor 13 which inspects the situation individually, and the heat transfer pipe positioning means 15 which measures the position of the heat transfer pipe 12 inspected by the pipe expansion inspection means 14. Hereinafter, these will be described in detail.

As shown in FIGS. 1 and 4, the tube expansion inspection means 14 is connected to an insertion jig (also referred to as an insertion gun) 16 that supports the eddy current sensor 13 to be inserted into the heat transfer tube 12 and the rear end portion of the eddy current sensor 13. Insertion / winding provided with an eddy current flaw detection cable 17, a rotating wheel (not shown) that moves the eddy current flaw detection cable 17 back and forth while contacting the outer peripheral portion, a rotation drive source of the rotation wheel, and an encoder that detects the rotation direction and the rotation speed of the rotation wheel. And a collector 18. Further, the tube expansion inspection means 14 includes an insertion / winding controller 19 that controls the operation of the rotational drive source of the insertion / winding device 18, an eddy current flaw detector 20 that detects eddy current generated in the eddy current sensor 13, and an eddy current. A tube expansion determination unit 21 that processes an output signal from the flaw detector 20 to detect a volume change of the tube expansion joint of the heat transfer tube 12 to determine the tube expansion connection state, and detection data and tube expansion state of the tube expansion determination unit 21 Display means 22 for converting the determination data into predetermined display data, and a display 23 for outputting the display data output from the display means 22.

With such a configuration, the eddy current sensor inlet / outlet 24 of the insertion jig 16 is brought into contact with the end of the heat transfer tube 12 joined to the tube plate 11, and the insertion / rewinding controller 19 issues an insertion / rewinding command. By rotating the rotating wheel of the winder 18, the eddy current flaw detection cable 17 can be inserted into the heat transfer tube 12 from the inserter / winder 18 at a constant speed and wound, whereby the eddy current sensor 13 can be wound. Can be inserted at a constant speed. At this time, the eddy current generated by the eddy current sensor 13 is detected by the eddy current flaw detector 20 and input to the pipe expansion determination unit 21 as an eddy current flaw detection output signal (ET output), and from the encoder via the insertion / winding controller 19. The output signal (E / C output) of the eddy current sensor 13 is also input to the tube expansion determination unit 21 so that the position of the eddy current sensor 13 in the heat transfer tube 12 (insertion distance from the end face of the heat transfer tube 12) can be always grasped. . For this reason, the volume change of the heat transfer tube 12 with respect to the distance from the end surface of the heat transfer tube 12, that is, the volume change of the pipe joint of the heat transfer pipe 12 can be detected, and the pipe joint state can be determined from the volume change. .

As shown in FIG. 1 and FIG. 2, the heat transfer tube positioning means 15 is ultrasonically sandwiched between the insertion jig 16, for example, between the eddy current sensor inlet / outlet 24 and the eddy current flaw detection cable inlet / outlet 25. The first ultrasonic transmitter 26 is arranged with a gap at a predetermined position on the tube plate 11 via a receiver holder 27 and a cylindrical first ultrasonic transmitter 26 that transmits a pulse. And first and second ultrasonic receivers 28 and 29 for receiving the ultrasonic pulses transmitted from 26. Here, the frequency of the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 is 30 to 50 kHz, for example, 40 kHz, and the transmission period of the ultrasonic pulse is 50 to 150 Hz, for example, 100 Hz. The first and second ultrasonic receivers 28 and 29 are each composed of an omnidirectional microphone (for example, a condenser microphone).

The receiver holder 27 is arranged so that the first and second ultrasonic receivers 28 and 29 have their sound receiving surfaces 30 on the inner side with respect to a straight line perpendicular to a central connection line connecting the centers of the sound receiving surfaces 30. 40 degrees or more and 50 degrees or less, for example, the 1st, 2nd receiver fixing bases 33 and 34 which are arrange | positioned inclining substantially 45 degree, and are fixed by the fixing members 31 and 32, and 1st, 2nd receiver Both ends have connecting members 36 connected to the first and second receiver fixing bases 33 and 34 through mounting screws (not shown) that are screwed into screw holes 35 formed in the fixing bases 33 and 34, respectively. is doing. Further, a handle 36 a for lifting the receiver holder 27 is attached to the upper surface of the connecting member 36, and protrusions 37 that can be inserted into the heat transfer tube 12 on both sides of the back surfaces of the first and second receiver fixing bases 33 and 34. Are installed respectively. Here, in the first and second receiver fixing bases 33 and 34, one projection 37 penetrates a long hole 37a formed in the longitudinal direction of the first and second receiver fixing bases 33 and 34. Yes. Thus, the distance between the pair of projections 37 is adjusted, and the projection 37 can be easily inserted into the heat transfer tube 12.
With such a configuration, the protrusion 37 provided on the back surface side of the first receiver fixing base 33 is inserted into the heat transfer tube 12 at a predetermined position, and the second receiver fixing base 34 is By inserting the projections 37 provided on the back side into the heat transfer tubes 12 at different predetermined positions, the first and second ultrasonic receivers 28 and 29 can be determined on the tube plate 11 in advance. It can arrange | position with a clearance gap in the position. In addition, you may arrange | position a 1st, 2nd ultrasonic receiver with a clearance gap in the predetermined position on the plane which extended the tube sheet.

Here, since the first and second ultrasonic receivers 28 and 29 are formed of omnidirectional microphones, the first and second ultrasonic receivers 28 and 28 are moved in accordance with the movement of the first ultrasonic transmitter 26. Even if the incident angle of the ultrasonic pulse incident on 29 greatly fluctuates, the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 can be reliably received. Therefore, the first ultrasonic transmitter 26 and the first and second ultrasonic receivers 28 and 29 can be disposed close to each other. Furthermore, since the first and second ultrasonic receivers 28 and 29 are made of omnidirectional microphones, the rising of the reception signal of the ultrasonic pulse becomes sharp. For this reason, the threshold level at the time of detecting a received signal can be set high, and the influence of noise due to external factors such as air flow can be removed to reliably detect the first wave. As a result, when the region where the first ultrasonic transmitter 26 is moved is constant, the first and second ultrasonic receivers 28 and 29 are arranged close to the moving region of the first ultrasonic transmitter 26. Thus, the ultrasonic pulse from the first ultrasonic transmitter 26 can be accurately detected.

As shown in FIGS. 1 to 5, the ultrasonic transmitter / receiver mounting base 61 has a first ultrasonic transmitter 26 in the vicinity of the tube plate 11, for example, with respect to the reception holder 27 disposed on the tube plate 11. A second ultrasonic transmitter 38 mounted on the tube plate 11 on the non-arranged side and mounted on one side in the longitudinal direction of the upper surface of the rectangular ultrasonic transmitter / receiver mounting base 61 in plan view, and ultrasonic transmission / reception A receiving surface is arranged opposite to the transmission surface of the second ultrasonic transmitter 38 so that an ultrasonic pulse from the second ultrasonic transmitter 38 can be received on the other longitudinal side of the upper surface of the child mount 61. The reception surface of the third ultrasonic receiver 39 and the ultrasonic transmitter / receiver mounting base 61 is placed at a position closer to the second ultrasonic transmitter 38 than the third ultrasonic receiver 39. A fourth ultrasonic receiver 62 disposed toward the transmission surface of the acoustic wave transmitter 38. . Here, the frequency of the ultrasonic pulse transmitted from the second ultrasonic transmitter 38 is 30 to 50 kHz, for example, 40 kHz, and the transmission cycle of the ultrasonic pulse is 50 to 150 Hz, for example, 100 Hz.

Reference numerals 63, 65, and 64 denote attachment members to which the second ultrasonic transmitter 38, the third ultrasonic receiver 39, and the fourth ultrasonic receiver 62 are attached, respectively, and reference numeral 66 denotes an attachment member 63. A mounting screw 65 is attached to the upper surface of the ultrasonic transceiver mounting base 61, a reference numeral 67 is a handle for lifting the ultrasonic transmitting / receiving base mounting base 61, and a reference numeral 68 is provided on both sides of the ultrasonic transmitting / receiving base mounting base 61. It is an insertion member that is inserted into the heat tube 12 and attaches the ultrasonic transceiver mounting base 61 onto the tube plate 11. One insertion member 68 passes through a long hole 69 formed in the longitudinal direction of the ultrasonic transceiver mounting base 61. Thereby, the distance between the insertion members 68 can be adjusted, and the installation direction of the ultrasonic transceiver mounting base 61 can be freely adjusted.

Further, the heat transfer tube positioning means 15 determines the vicinity of the tube plate 11 from the time required for the ultrasonic pulse transmitted from the second ultrasonic transmitter 38 to reach the third and fourth ultrasonic receivers 39 and 62. The propagation time t ₁ , t required for the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 to reach the first and second ultrasonic receivers 28 and 29 is measured. ₂ is provided, and an insertion jig position calculation unit 40 is provided for calculating and storing a planar position of the insertion jig 16 on the tube plate 11 from the ultrasonic wave propagation speed and the propagation times t ₁ and t ₂ . . In addition, the data processor 41 is comprised by the pipe expansion joining determination part 21, the display means 22, the indicator 23, and the insertion jig position calculating part 40. FIG. Here, the data processor 41 can be formed by, for example, mounting a program that expresses the functions of the tube expansion determination unit 21, the display unit 22, and the insertion jig position calculation unit 40 on a personal computer.

Further, the heat transfer tube positioning means 15 includes pulsars 42 and 43 for driving the first and second ultrasonic transmitters 26 and 38, and a reference clock 44 for outputting a trigger signal for starting driving to the pulsars 42 and 43, respectively. , Preamplifiers 45 to 47 and 70 for amplifying output signals from the first to fourth ultrasonic receivers 28, 29, 39 and 62, and preamplifiers 45 and 46 and preamplifiers in synchronization with the operations of the pulsars 42 and 43. A multiplexer 48 that extracts the output signals from 47 and 70, a filter 49 that removes noise from the output signal extracted through the multiplexer 48, and the difference in propagation distance of the ultrasonic pulse between the output signals from the filter 49 The interface unit 51 is provided with a DAC circuit 50 that electronically compensates for the deterioration due to. In the interface unit 51, the output signal of the DAC circuit 50, the trigger signal from the reference clock 44, the output signal from the encoder of the insertion / winding device 18 and the output signal from the eddy current flaw detector 20 are converted into digital signals. A high-speed AD board 52 for converting and outputting is provided.

Here, the insertion jig position calculation unit 40 has tube arrangement position data of the heat transfer tubes 12 on the tube plate 11 (for example, coordinate data of each heat transfer tube 12 when a specific point on the tube plate 11 is set as the origin). The first and second ultrasonic pulses transmitted from the first ultrasonic transmitter 26 are the tube arrangement position data of the heat transfer tubes 12 into which the pair of protrusions 37 provided on the back surface side of the receiver holder 27 are inserted. Position data of the first ultrasonic transmitter 26, the first ultrasonic receiver 28, and the second ultrasonic receiver 28 when the ultrasonic receivers 28 and 29 are used to measure the ultrasonic propagation velocity near the tube plate 11. A data input unit 53 for inputting position data of the second ultrasonic transmitter 38, the third and fourth ultrasonic receivers 39 and 62, and a data storage unit for storing data input from the data input unit 53 54.

Further, the insertion jig position calculation unit 40 obtains the time required for the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 to reach the first and second ultrasonic receivers 28 and 29. Based on the position data of the first ultrasonic transmitter 26 and the first and second ultrasonic receivers 28 and 29 stored in the data storage 54, the ultrasonic propagation velocity in the vicinity of the tube plate 11 is obtained and stored. And the propagation time t required for the ultrasonic pulse transmitted from the second ultrasonic transmitter 38 to reach the third and fourth ultrasonic receivers 39 and 62. ₃ , t ₄ is measured to check whether there is a change in the ultrasonic propagation velocity in the vicinity of the tube plate 11. If the ultrasonic propagation velocity in the vicinity of the tube plate 11 changes, the new ultrasonic propagation velocity in the vicinity of the tube plate 11 The new ultrasonic wave propagation velocity is obtained and stored in the data memory 54. And a sound velocity corrector 55a for updating the ultrasonic wave propagation velocity of the plate 11 near the tube sheet 11 to a new ultrasonic wave propagation velocity in the vicinity.

Further, the insertion jig position calculation unit 40 has a propagation time t ₁ required for the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 to reach the first and second ultrasonic receivers 28 and 29. , T ₂ , respectively, and inserted from the ultrasonic propagation velocity stored in the data storage 54, the tube arrangement position data of the heat transfer tube 12, and the position data of the first and second ultrasonic receivers 28 and 29. And a jig position calculator 56 for calculating and storing a planar position of the jig 16 on the tube plate 11.

Next, the operation of the sound speed calculation setter 55 will be described in detail.
The propagation speed of the ultrasonic wave propagating in the air is affected by temperature and humidity, but the accuracy required for calculating the planar position of the insertion jig 16 on the tube plate 11 (for example, within a square region having a side of 1200 mm) In view of the error of the planar position at 10 mm or less), the influence of the humidity is small, so that the influence of the temperature can be substantially taken into consideration. Therefore, if the propagation speed of the ultrasonic wave affected by temperature is V and the propagation distance is S, the relationship between the propagation speed V and the distance S is generally as follows: t is the time required for propagation and C is a constant (offset). It can be expressed by equation (1).
S = Vt + C (1)

Therefore, in the sound speed calculation setting unit 55, for example, the positions of the first and second ultrasonic receivers 28 and 29 are fixed, and the first ultrasonic transmitter 26 is connected to the first and second ultrasonic receivers 28. 29, a first position that is a distance S ₁ from the first, and a second position that is a distance S ₂ from the first and second ultrasonic receivers 28 and 29, and transmits an ultrasonic pulse, The time required to reach the second ultrasonic receivers 28 and 29 is measured. Here, when the first ultrasonic transmitter 26 is arranged at the first position, the time until reaching the first ultrasonic receiver 28 is t ₁₁ , and the first ultrasonic transmission is transmitted to the second position. When the time to reach the first ultrasonic receiver 28 when the child 26 is arranged is t ₁₂ , the relationship of the equation (1) is S ₁ = V ₁ t ₁₁ + C ₁ , S ₂ = V ₁ From t ₁₂ + C ₁ , the ultrasonic wave propagation velocity V ₁ and constant C ₁ are obtained. In addition, when the first ultrasonic transmitter 26 is arranged at the first position, the time until reaching the second ultrasonic receiver 29 is t ₂₁ , and the first ultrasonic transmission is transmitted to the second position. Assuming that the time to reach the second ultrasonic wave receiver 29 when the child 26 is arranged is t ₂₂ , the relationship of equation (1) is S ₁ = V ₂ t ₂₁ + C ₂ , S ₂ = V ₂ From t ₂₂ + C ₂ , the ultrasonic wave propagation velocity V ₂ and constant C ₂ are obtained. The obtained V ₁ , C ₁ , V ₂ , and C ₂ are input to the data memory 54.

Next, the operation of the sound speed corrector 55a will be described in detail.
The sonic speed corrector 55a measures the times t and p required for the ultrasonic pulse to reach the third and fourth ultrasonic receivers 39 and 62 from the second ultrasonic transmitter 38, thereby measuring the ultrasonic wave. The propagation velocity V and the constant C are obtained. Then, using the obtained ultrasonic propagation velocity V and the time t required for the ultrasonic pulse to reach the third ultrasonic receiver 39 from the second ultrasonic transmitter 38, the equation (1) is used. By confirming the distance from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 based on the relationship, the influence of the propagation velocity V accompanying the temperature change is detected.

First, when the sound speed corrector 55a is switched on, ultrasonic pulses are transmitted from the second ultrasonic transmitter 38 toward the third and fourth ultrasonic receivers 39 and 62. Here, the propagation times of the ultrasonic pulses are the rising times of the second ultrasonic transmitter TRG output signal and the third and fourth ultrasonic receiver output signals output from the high-speed AD board 52 as a pair. It is obtained as the time difference between The distance from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 is a predetermined value S ₀ , and the distance from the second ultrasonic transmitter 38 to the fourth ultrasonic receiver 62 is predetermined. Since the value U ₀ is set, the average time t ₀ required for the ultrasonic pulse to propagate from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 is the second ultrasonic transmitter 38. When the average time p ₀ required for the ultrasonic pulse to propagate to the fourth ultrasonic receiver 62 is obtained, the relationship of S ₀ = V ₀ t ₀ + C ₀ and U ₀ = V ₀ p ₀ + C ₀ is obtained. From these relationships, the propagation speed V _{0 of the} ultrasonic pulse and the constant C ₀ are determined, and the distance S ₀ from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 is:
S ₀ = V ₀ t ₀ + C ₀ (2)
It is obtained.

The sound velocity corrector 55 a inputs the obtained propagation velocity V ₀ as the ultrasonic propagation velocity V to the data storage device 54 and directs it from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39. Then, the propagation time of the ultrasonic pulse transmitted is measured, and the distance S ₀ from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 is determined from the propagation velocity V ₀ based on the equation (2). Always check.

Next, the temperature of the air changes and the ultrasonic propagation velocity V ₀ changes by ΔV, and accordingly, the ultrasonic pulse propagates from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39. Is changed by -Δt. Here, since the sound speed corrector 55a confirms the distance S ₀ from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 using the equation (2), the second ultrasonic wave is confirmed. When the time required for the ultrasonic wave to propagate from the transmitter 38 to the third ultrasonic receiver 39 changes by −Δt, as shown by the equation (3), the second ultrasonic transmitter 38 to the third ultrasonic wave It is determined that the distance to the sound wave receiver 39 has changed to S ′.
S ′ = V ₀ × (t ₀ −Δt) + C ₀ (3)
However, since the ultrasonic wave propagation speed is actually V ₀ + ΔV and the distance S ₀ is propagated at the propagation time t ₀ -Δt, the relationship shown in the equation (4) is established.
S ₀ = (V ₀ + ΔV) × (t ₀ −Δt) + C ₀ (4)

Therefore, the sound speed corrector 55a calculates the absolute value of the difference between S ₀ and S ′ set in advance, and this value is necessary for calculating the planar position of the insertion jig 16 on the tube plate 11. If the accuracy is exceeded, ΔV = V ₀ × (S ₀ −S ′) / (S′−C ₀ ) (5) from the equations (3) and (4).
As well as input to the data storage device 54 seeking to update the V ₀ to V ₀ + ΔV. In the data storage 54, the stored ultrasonic wave propagation speeds V ₁ and V ₂ in the vicinity of the tube plate 11 are updated and stored as V ₁ + ΔV and V ₂ + ΔV, respectively.
The ultrasonic transceiver mounting base 61 is mounted on the tube plate 11 on the side where the first ultrasonic transmitter 26 is not disposed with respect to the reception holder 27 disposed on the tube plate 11. Is not limited to the tube plate 11. Here, the vicinity of the tube sheet is a range in which an ultrasonic wave propagation velocity is ensured so as not to affect the calculation accuracy of the planar position of the insertion jig 16 on the tube plate 11, for example, one side is 1200 mm. When the error of the planar position in the square region is 10 mm or less, the temperature difference with the temperature on the tube sheet is within ± 3 ° C.

Next, the operation of the jig position calculator 56 will be described in detail.
In the jig position calculator 56, the propagation times t ₁ and t ₂ required for the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 to reach the first and second ultrasonic receivers 28 and 29 are obtained. For each. Here, the propagation times t ₁ and t ₂ are calculated from the first ultrasonic transmitter TRG output signal and the first and second ultrasonic receiver output signals output from the high-speed AD board 52 as a pair. It is obtained as the time difference of the rise time of the signal.

In addition, when calculating | requiring the time difference of the rise time of each signal, for example, 30-80 ultrasonic pulses are transmitted continuously from the ultrasonic pulse transmitted from the 1st ultrasonic transmitter 26, and the 1st, 1st The difference between the rising times of the first ultrasonic transmitter TRG output signal and the first and second ultrasonic receiver output signals is received by the two ultrasonic receivers 28 and 29 for each ultrasonic pulse. These average values are used as the time difference between the rising times of the first ultrasonic transmitter TRG output signal and the first and second ultrasonic receiver output signals, respectively. As a result, the influence of ambient noise is reduced and the propagation times t ₁ and t ₂ can be accurately obtained. Then, when the propagation times t ₁ and t ₂ are obtained, the first ultrasonic transmitter 26 and the first ultrasonic transmitter 26 are connected to the first ultrasonic transmitter 26 using the V ₁ , C ₁ , V ₂ and C ₂ stored in the data memory 54. The distance W ₁ to the ultrasonic receiver 28 is calculated from V ₁ t ₁ + C ₁ , and the distance W ₂ to the first ultrasonic transmitter 26 and the second ultrasonic receiver 29 is calculated from V ₂ t ₂ + C _2. To do.

On the other hand, since the distance L between the first and second ultrasonic receivers 28 and 29 is fixed, for example, the central position of the sound receiving surface 30 of the first ultrasonic receiver 28 is set to the origin O ′ for measurement. Then, the coordinates (x, y) of the center position of the first ultrasonic transmitter 26 are
x = (W ₁ ² −y ² ) ^1/2 (6)
y = (W ₁ ² −W ₂ ² + L ² ) / 2L (7)
It is obtained.

Here, by inserting the projection 37 of the receiver holder 27 into each heat transfer tube 12 at a predetermined position, the first and second ultrasonic receivers 28 and 29 are determined on the tube plate 11 in advance. For example, the center position of the sound receiving surface 30 of the first ultrasonic receiver 28, that is, the measurement origin O ′ and the second ultrasonic receiver 29 are fixed. The positional relationship with the center position of the heat transfer tube 12 in which the protrusion 37 of the second receiver fixing base 34 is inserted is obtained. On the other hand, since the center position of the heat transfer tube 12 into which the projection 37 of the second receiver fixing base 34 is inserted is obtained from the tube arrangement position data of the heat transfer tube 12 on the tube plate 11, the tube arrangement position data is created. The center position coordinates (X, Y) of the first ultrasonic transmitter 26 with respect to the determined origin O are determined. Therefore, by comparing the tube arrangement position data with the center position coordinates (X, Y) of the first ultrasonic transmitter 26, the position of the heat transfer tube 12 on which the tube expansion inspection is performed on the tube plate 11 is the first. This can be determined by obtaining a planar position on the tube plate 11 of the insertion jig 16 provided with the ultrasonic transmitter 26.

Then, each time the pipe expansion inspection is performed, the position is determined on the tube plate 11 of the heat transfer tube 12 to be subjected to the pipe expansion inspection to obtain position determination data, and the pipe plate 11 of the heat transfer pipe 12 that has been inspected every time the pipe expansion inspection is completed. When the above positions are sequentially stored in the jig position calculator 56 as heat transfer pipe position data, the position determination data of the heat transfer pipe 12 to be subjected to the pipe expansion inspection and the pipe expansion inspection stored in the jig position calculator 56. When the heat exchanger tube position data that has already been output is output to the display 23 via the display means 22, for example, the heat transfer tube that has undergone pipe expansion inspection is shown in the heat transfer tube layout diagram showing the state of the heat transfer tubes 12 arranged on the tube plate 11. The position and the position of the heat transfer tube during the pipe expansion inspection can be superimposed and displayed.

Then, the usage method of the pipe expansion confirmation test | inspection apparatus 10 which concerns on one embodiment of this invention is demonstrated.
As shown in FIGS. 5A to 5C, the first and second receiver holders 27 are placed in the heat transfer tube 12 at a predetermined position outside the region to be inspected on the tube plate 11. The receiver holders 27 are arranged on the tube plate 11 by inserting the protrusions 37 provided on the back side of the receiver receiver fixing bases 33 and 34. In addition, the insertion member 68 is inserted into the heat transfer tube 12 existing outside near the receiving holder 27, and the ultrasonic transceiver mounting base 61 is disposed on the tube plate 11.

Next, the output signal of the DAC circuit 50 of the interface unit 51 and the trigger signal from the reference clock 44 are input to the sound speed calculation setting unit 55 by operating a changeover switch (not shown). The insertion jig 16 tube sheet 11 the first ultrasonic transmitter transducer 26 is moved on the first first position where the distance S ₁ from the ultrasonic receiver 28, the distance S ₂ become the second The ultrasonic wave is transmitted to the first ultrasonic wave transmitter 26 and the first ultrasonic wave transmitter 26 and the first ultrasonic wave transmitter 26 by measuring the time required to reach the first ultrasonic wave receiver 28 by the sound speed calculation setting unit 55. The ultrasonic wave propagation velocity V ₁ and constant C ₁ in the equation (1) established between one ultrasonic receiver 28 are obtained. In addition, the first ultrasonic transmitter 26 is arranged at a first position at a distance S ₁ and a second position at a distance S ₂ from the second ultrasonic receiver 29 to transmit ultrasonic pulses, respectively. By measuring the time until the second ultrasonic receiver 29 is reached by the sound speed calculation setting unit 55, the first ultrasonic transmitter 26 and the second ultrasonic receiver 29 are established ( 1) Find V ₂ and C ₂ in the equation. The obtained V ₁ , C ₁ , V ₂ , and C ₂ are input to the data memory 54. Further, the sound speed corrector 55a measures the time required for propagation of the ultrasonic pulse by transmitting the ultrasonic pulse from the second ultrasonic transmitter 38 to the third and fourth ultrasonic receivers 39 and 62. From the distance S ₀ from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39 and the distance U ₀ from the second ultrasonic transmitter 38 to the fourth ultrasonic receiver 62, ( The ultrasonic wave propagation velocity V ₀ and constant C ₀ in the equation (2) are obtained.

Subsequently, the output signal of the DAC circuit 50 of the interface unit 51 and the trigger signal from the reference clock 44 are input to the jig position calculator 56 by operating a changeover switch (not shown). Then, the eddy current sensor inlet / outlet 24 of the insertion jig 16 is brought into contact with the end of the heat transfer tube 12 to start the inspection, and the eddy current sensor 13 is inserted into the heat transfer tube 12. Reference numeral 57 denotes an ultrasonic transmission cable that transmits an ultrasonic pulse generation signal from the pulser 42 to the first ultrasonic transmitter 26. Then, when the inspection start switch 58 provided in the insertion jig 16 is turned on, the insertion / winding device 18 is driven under the conditions set in the insertion / winding controller 19, and the eddy current flaw detection cable 17 is moved by the measurement length. Pull out at a constant speed after extrusion. Thereby, the movement of the eddy current sensor 13 in the heat transfer tube 12 is started, and the pipe expansion inspection is started.

Then, the sound speed corrector 55a obtains the propagation time of the ultrasonic pulse transmitted from the second ultrasonic transmitter 38 to the third ultrasonic receiver 39, and determines the propagation speed V _0. A distance S ₀ between the second ultrasonic transmitter 38 and the third ultrasonic receiver 39 is confirmed. When the propagation time changes by -Δt, the distance S ₀ between the second ultrasonic transmitter 38 and the third ultrasonic receiver 39 changes to S ′, so the absolute difference between S ₀ and S ′ is absolute. If the value exceeds a preset value range (5 mm to 10 mm, for example, 8 mm), ΔV (= V ₀ × (S ₀ −S ′) / (S′−C ₀ )) is obtained. And V ₀ is updated to V ₀ + ΔV. In the data memory 54, the stored ultrasonic propagation velocities V ₁ and V ₂ near the tube plate 11 are updated and stored as V ₁ + ΔV and V ₂ + ΔV, respectively.

When the pulser 42 is driven via the reference clock 44 to transmit ultrasonic pulses from the first ultrasonic transmitter 26 to the first and second ultrasonic receivers 28 and 29, the first The positional relationship between the ultrasonic transmitter 26 and the first and second ultrasonic receivers 28 and 29 is as shown in FIG. 6 (A), and is displayed on the display 23 via the display means 22. The reception signals of the ultrasonic pulses received by the second ultrasonic receivers 28 and 29 become a waveform image 59 shown in FIG. Then, the propagation times t ₁ and t required for the ultrasonic pulse transmitted from the first ultrasonic transmitter 26 by the jig position calculator 56 to reach the first and second ultrasonic receivers 28 and 29 are as follows. ₂ is obtained, the distance between the first ultrasonic transmitter 26 and the first ultrasonic receiver 28 using V ₁ , C ₁ , V ₂ , and C ₂ stored in the data memory 54. W ₁ is V ₁ t ₁ + C ₁ , the distance W ₂ between the first ultrasonic transmitter 26 and the second ultrasonic receiver 29 is determined as V ₂ t ₂ + C ₂ , and the first ultrasonic receiver The coordinates (x, y) of the center position of the first ultrasonic transmitter 26 when the center position of the 28 sound receiving surfaces 30 is the origin O ′ for measurement are obtained.

Here, when the protrusion 37 of the receiver holder 27 is inserted into each heat transfer tube 12 at a predetermined position, the measurement origin O ′ and the second ultrasonic receiver 29 are fixed to the second receiver. The positional relationship with the center position of the heat transfer tube 12 in which the protrusion 37 of the fixing base 34 is inserted is determined, and the center position of the heat transfer tube 12 in which the protrusion 37 of the second receiver fixing base 34 is inserted is the tube plate. 11, the center position coordinates (X, Y) of the first ultrasonic transmitter 26 with respect to the origin O determined at the time of creating the tube array position data are determined. Therefore, when the data of the center position coordinates (X, Y) of the first ultrasonic transmitter 26 and the heat transfer tube layout diagram of the heat transfer tube 12 on the tube plate 11 are superimposed and displayed using the display means 22, A heat transfer tube arrangement image 60 shown in FIG. 6B is obtained on the display 23.

Then, the reference clock 44 is stopped to stop the transmission of ultrasonic pulses from the first and second ultrasonic transmitters 26 and 38, and the center position coordinates (X, Y) of the first ultrasonic transmitter 26 are stopped. ) And the tube arrangement position data, the heat transfer tube having the center position coordinate that matches the center position coordinate (X, Y) of the first ultrasonic transmitter 26 within the accuracy range is specified. The heat transfer tube position data of the heat tube 12 is stored in the jig position calculator 56 as a tube transfer inspected heat transfer tube.

When the eddy current sensor 13 returns to the initial position when the tube expansion inspection on the end side of the heat transfer tube 12 is started and it is confirmed that an inspection completion lamp (not shown) is lit, the eddy current sensor inlet / outlet 24 of the insertion jig 16 is opened. The heat transfer tube 12 is separated from the heat transfer tube 12 that has been subjected to the pipe expansion inspection, the vortex sensor inlet / outlet 24 is brought into contact with the end of the heat transfer tube 12 to be inspected next, and the vortex sensor 13 is inserted into the heat transfer tube 12. Then, the inspection start switch 58 is turned on to start the pipe expansion inspection. By repeating the above operation, every time the pipe expansion inspection is performed, the position is obtained on the tube plate 11 of the heat transfer pipe 12 to be subjected to the pipe expansion inspection, and the heat transfer pipe position data of the heat transfer pipe 12 after the pipe expansion inspection is calculated as the jig position calculation. The data are sequentially stored in the device 56. Therefore, when the pipe expansion inspection proceeds, the position determination data of the heat transfer pipe 12 performing the pipe expansion inspection in the jig position calculator 56 and the heat transfer pipe position data subjected to the pipe expansion inspection are displayed on the display unit 23 via the display means 22. When output, as shown in FIG. 7, the heat transfer tube layout showing the state of the heat transfer tubes 12 arranged on the tube plate 11 is overlapped with the heat transfer tube position after the pipe expansion inspection and the heat transfer pipe position during the pipe expansion inspection. They can be displayed together, and the progress of the tube expansion inspection can be easily confirmed.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. A case where the tube expansion confirmation inspection apparatus of the present invention is configured by combining some or all of the forms and the modifications is also included in the scope of the right of the present invention.

It is a block diagram of the pipe expansion confirmation inspection apparatus concerning one embodiment of the present invention. It is explanatory drawing of the receiver holder which attaches the 1st, 2nd ultrasonic receiver used with the said pipe expansion confirmation inspection apparatus. It is explanatory drawing of the ultrasonic transmitter-receiver mounting base which attaches the 2nd ultrasonic transmitter used in the said pipe expansion confirmation test | inspection apparatus and the 3rd, 4th ultrasonic receiver. It is a block diagram of the data processor of the pipe expansion confirmation inspection apparatus. (A)-(C) are explanatory drawings of the usage method of the said pipe expansion confirmation test | inspection apparatus. (A) is explanatory drawing of the processing content in the insertion jig position calculating part of the said pipe expansion confirmation inspection apparatus, (B) is the position on the tube board of a 1st ultrasonic transmitter, and 1st, 2nd ultrasonic waves. It is explanatory drawing of the indicator screen which displayed the condition of the ultrasonic pulse each received with the receiver. It is explanatory drawing of the display screen which displayed the pipe expansion test | inspection status by the said pipe expansion confirmation inspection apparatus.

Explanation of symbols

10: tube expansion confirmation inspection device, 11: tube sheet, 12: heat transfer tube, 13: eddy current sensor, 14: tube expansion inspection means, 15: heat transfer tube positioning means, 16: insertion jig, 17: eddy current flaw detection cable, 18: insertion / Winding device, 19: insertion / winding controller, 20: eddy current flaw detector, 21: expansion joint determination unit, 22: display means, 23: indicator, 24: eddy current sensor inlet / outlet, 25: eddy current flaw detection cable inlet / outlet, 26: first ultrasonic transmitter, 27: receiver holder, 28: first ultrasonic receiver, 29: second ultrasonic receiver, 30: sound receiving surface, 31, 32: fixing member, 33 : First receiver fixing base, 34: second receiver fixing base, 35: screw hole, 36: connecting member, 36a: handle, 37: protrusion, 37a: long hole, 38: second ultrasonic transmission Child, 39: third ultrasonic wave receiver, 40: insertion jig position calculation unit, 41: data Data processor, 42, 43: pulser, 44: reference clock, 45-47: preamplifier, 48: multiplexer, 49: filter, 50: DAC circuit, 51: interface unit, 52: high-speed AD board, 53: data input , 54: data storage device, 55: sound speed calculation setting device, 55a: sound speed correction device, 56: jig position calculation device, 57: ultrasonic transmission cable, 58: inspection start switch, 59: waveform image, 60: transmission Heat tube arrangement image, 61: ultrasonic transceiver mounting base, 62: fourth ultrasonic receiver, 63, 64, 65: mounting member, 66: mounting screw, 67: handle, 68: insertion member, 69: long hole , 70: Preamplifier

Claims (3)

Tube expansion inspection means having an eddy current sensor that individually inspects the joining state of a large number of heat transfer tubes that are expanded and joined to the tube plate of the heat exchanger, and a heat transfer tube that measures the position of the heat transfer tube inspected by the tube expansion inspection means A pipe expansion confirmation inspection device having positioning means,
The heat transfer tube positioning means is a part of the tube expansion inspection means, and is attached to an insertion jig that supports the eddy current sensor inserted into the heat transfer pipe, and transmits an ultrasonic pulse around the insertion jig. A first ultrasonic transmitter;
First and second receiving ultrasonic pulses transmitted from the first ultrasonic transmitter are arranged with a gap at a predetermined position on the tube plate or on a plane extending from the tube plate. Two ultrasonic receivers;
A second ultrasonic transmitter provided in the vicinity of the tube sheet;
Third and fourth ultrasonic receivers arranged with a gap in the vicinity of the tube plate and receiving ultrasonic pulses transmitted from the second ultrasonic transmitter;
Propagation times t ₁ and t ₂ required for the ultrasonic pulse transmitted from the first ultrasonic transmitter to reach the first and second ultrasonic receivers are respectively determined and stored in advance. An insertion jig position calculation unit that calculates and stores a planar position of the insertion jig on the tube plate from the ultrasonic wave propagation velocity in the vicinity of the tube plate and the propagation times t ₁ and t ₂ ;
In addition, the insertion jig position calculation unit has a propagation time t ₃ required for the ultrasonic pulse transmitted from the second ultrasonic transmitter to reach the third and fourth ultrasonic receivers, From the measurement of t _4, the presence or absence of a change in the ultrasonic propagation velocity near the tube plate is confirmed. If the ultrasonic propagation velocity near the tube plate changes, a new ultrasonic propagation velocity near the tube plate is obtained and stored. A tube expansion confirmation inspection apparatus, comprising: a sound speed corrector for updating the ultrasonic propagation velocity in the vicinity of the tube plate to a new ultrasonic propagation velocity in the vicinity of the tube plate. 2. The tube expansion confirmation inspection device according to claim 1, wherein an omnidirectional microphone is used for the first and second ultrasonic receivers. 3. The tube expansion confirmation inspection apparatus according to claim 2, wherein the sound receiving surfaces of the omnidirectional microphones are 40 degrees or more and 50 degrees or less inward with respect to a straight line perpendicular to a central connection line that connects the centers of the sound receiving surfaces. Tube expansion confirmation inspection device characterized by being placed at an angle.

Images