U.S. patent application number 13/172226 was filed with the patent office on 2012-01-05 for traversing in-core probe drive unit and method for monitoring friction of inside of guide tubes.
Invention is credited to Hiromi Kato, Hidehiko YASUTA.
Application Number | 20120001012 13/172226 |
Document ID | / |
Family ID | 45098832 |
Filed Date | 2012-01-05 |
United States Patent
Application |
20120001012 |
Kind Code |
A1 |
YASUTA; Hidehiko ; et
al. |
January 5, 2012 |
Traversing In-Core Probe Drive Unit and Method for Monitoring
Friction of Inside of Guide Tubes
Abstract
A TIP drive unit that calculates a cable drive torque stably is
provided. In accordance with the invention, Traversing In-core
Probe (TIP) drive unit includes a housing, a storage reel
configured to storage the probe cable, a drive mechanism including
a motor, and configured to feed the probe cable form the storage
reel and spool the probe cable onto the storage reel, a motor
controller configured to drive the motor at a predefined rotating
speed, a processor configured to calculate a cable drive torque
that is a torque necessary for moving the TIP and the probe cable
by using a value of supply power necessary for driving the motor, a
value of the predefined rotating speed of the motor, and a loss
torque that is a torque necessary for driving the drive mechanism,
and a noise filter configured to remove noise included in a signal
indicating the value of the supply power.
Inventors: |
YASUTA; Hidehiko;
(Kanagawa-ken, JP) ; Kato; Hiromi; (Kanagawa-ken,
JP) |
Family ID: |
45098832 |
Appl. No.: |
13/172226 |
Filed: |
June 29, 2011 |
Current U.S.
Class: |
242/563 |
Current CPC
Class: |
G21C 17/10 20130101;
Y02E 30/30 20130101 |
Class at
Publication: |
242/563 |
International
Class: |
B65H 43/00 20060101
B65H043/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2010 |
JP |
P2010-150436 |
Claims
1. A Traversing In-core Probe (TIP) drive unit for moving a TIP
connected to an edge of a probe cable in a guide tubes, comprising:
a housing having an introduction path; a storage reel provided in
the housing, and configured to storage the probe cable; a drive
mechanism provided in the housing, including a motor, and
configured to feed the probe cable from the storage reel and spool
the probe cable onto the storage reel through the introduction
path; a motor controller configured to supply a supply power to the
motor, and drive the motor at a predefined rotating speed; a
processor configured to calculate a cable drive torque for moving
the TIP and the probe cable in the guide tubes by using the supply
power for driving the motor by the motor controller, the predefined
rotating speed of the motor, and a loss torque for driving the
drive mechanism; and a noise filter configured to remove noise
included in a signal indicating the supply power.
2. The TIP drive unit of claim 1, wherein the motor controller
includes an inverter configured to drive the motor, and wherein the
noise filter is a low-pass filter configured to remove
high-frequency noise generated by the inverter.
3. The TIP drive unit of claim 1, wherein the motor controller
includes an inverter configured to drive the motor, and wherein the
noise filter is a low-pass filter configured to remove higher
frequency noise than power-supply frequency of the inverter.
4. The TIP drive unit of claims 2 and 3, wherein the inverter has a
larger electric capacity than necessary for an usual flux
measurement.
5. The TIP drive unit of claim 1, wherein the motor controller is
configured to drive the motor at a various speed, and wherein the
processor configured to calculate the cable drive torque by using
the loss-torque depending on the various rotating speed.
6. The TIP drive unit of claim 4, wherein the motor controller is
configured to move the TIP at high-speed in the guide tube and move
the TIP at low-speed in the calibration tube.
7. The TIP drive unit of claim 1, further comprising: a function
configured to homologize the cable drive torque and a position of
the TIP and the probe cable where the cable drive torque was
measured.
8. The TIP drive unit of claim 1, wherein the processor is
configured to compare the cable drive torque and a normal cable
drive torque, and determine the position where a lubricant fell
away in the guide tube.
9. A method for monitoring friction of inside of guide tubes,
comprising: moving a TIP and a probe cable by a drive mechanism
including a motor in the guide tubes; measuring a value of supply
power necessary for driving the motor and a value of the predefined
rotating speed of the motor; calculating a cable drive torque that
is a torque necessary for moving the TIP and the probe cable in the
guide tubes by using the supply power for driving the motor, the
predefined rotating speed of the motor, and a loss torque for
driving the drive mechanism; and removing a noise included in a
signal indicating the supply power.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2010-150436, filed on
Jun. 30, 2010, the entire content of which is incorporated herein
by reference.
FIELD OF THE INVENTION
[0002] The present invention is a Traversing in-core probe (TIP)
drive unit that moves a TIP in a nuclear reactor by feeding and
spooling a probe cable in the reactor. More particularly, the
invention is directed to a TIP drive unit that calculates a cable
drive torque stably.
BACKGROUND OF THE INVENTION
[0003] In order to measure neutron flux distribution in a nuclear
reactor, Local Power Range Monitors (LPRMs) are provided in the
reactor. However, the LPRMs are placed in the reactor constantly
and difficult to be replaced, and the sensitivity of the LPRMs
declines with time. Therefore, the sensitivity of LPRMs needs to be
calibrated arbitrarily in order to measure neutron flux
distribution in the reactor exactly.
[0004] In order to calibrate sensitivity of the LPRMs, a Traversing
In-core Prove (TIP) system is provided in the nuclear power plant.
The TIP system moves a TIP in calibration tubes provided in the
reactor, and a TIP measures neutron flux in the proximity of the
LPRMs with moving. By using measuring result of neutron flux, the
sensitivity of the LPRMs is calibrated.
[0005] The TIP is attached to an edge of a probe cable, and a drive
mechanism included in the TIP system moves the TIP in the
calibration tubes and in guide tubes introducing the TIP to the
calibration tubes by feeding from a storage reel and spooling the
probe cable onto the storage reel.
[0006] The calibration tubes provided vertically in the reactor and
a shape of each guide tube is curved so as to introduce the TIP
into the corresponding calibration tube from outside of a pedestal
of the reactor. Therefore, in order to reduce friction while the
TIP and the probe cable move in the guide tube, the inside of the
guide tubes are coated with lubricant.
[0007] This lubricant may fall away or may be diminished due to
moving of the TIP and the probe cable. In the result, there is a
possibility of damaging the TIP and the probe cable when the TIP
and the probe cable move at a position where the lubricant fell
away. Therefore, the friction at inside of the guide tubes caused
by moving of the TIP and the probe cable is measured regularly by
measuring cable drive torque, which is torque necessary for feeding
and spooling the probe cable.
[0008] Previously, utility workers attach a torque wrench to a
motor shaft in the TIP system, and measure the cable drive torque.
However, the measurements may vary among utility workers. Moreover,
because the probe cable in the TIP system is radioactivated, there
is a possibility that utility workers are exposed to radiation when
the measurement takes a long time.
[0009] Japanese Patent Laid-open Publication No. 2002-71483
discloses a TIP system having a torque sensor attached to the motor
shaft in the TIP system. And this torque sensor measures cable
drive torque automatically.
[0010] However, in this TIP system, due to deterioration of the
torque sensor, it is difficult to calculate the cable drive torque
stably.
[0011] Furthermore, Japanese Patent Laid-open Publication No. Syo
63-163196 discloses a TIP system having a processor calculating the
cable drive torque automatically by using a value of supply power
to the motor, a predefined rotating speed of the motor, and a loss
torque that is a torque necessary for driving a drive mechanism
including the motor.
[0012] However, in this TIP system, an inverter driving the motor
generates high-frequency noise, and the signal indicating
fluctuations of torque may hide amongst this noise. In the result,
it is difficult to calculate the cable drive torque exactly.
SUMMARY OF THE INVENTION
[0013] Accordingly, it is an object of the invention to provide a
TIP system that calculates the cable drive torque stably.
[0014] In accordance with the invention, Traversing In-core Probe
(TIP) drive unit includes a housing having an introduction path, a
storage reel provided in the housing, and configured to storage the
probe cable, a drive mechanism provided in the housing, including a
motor, and configured to feed the probe cable from the storage reel
and spool the probe cable onto the storage reel through the
introduction path, a motor controller configured to drive the motor
at a predefined rotating speed, a processor configured to calculate
a cable drive torque that is a torque necessary for moving the TIP
and the probe cable in the guide tubes by using a value of supply
power necessary for driving the motor by the motor controller, a
value of the predefined rotating speed of the motor, and a loss
torque that is a torque necessary for driving the drive mechanism,
and a noise filter configured to remove noise included in a signal
indicating the value of the supply power.
[0015] Additional objects and advantages of the invention will be
set forth in part in the description which follows, and in part
will be obvious from the description, or may be learned by practice
of the invention. The objects and advantages of the invention will
be realized and attained by means of the elements and combinations
particularly pointed out in the appended claims.
[0016] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention, as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawing, which is incorporated in and
constitute a part of the specification, illustrates an embodiment
of the invention and together with the description, serve to
explain the principles of the invention.
[0018] FIG. 1 is a block schematic diagram illustrating a TIP drive
unit according to one embodiment of the invention.
[0019] FIG. 2 is a graphic representation illustrating all-torque
and cable drive torque against insert distance of the TIP into the
guide tubes.
[0020] FIG. 3 is a graphic representation illustrating all-torque
and cable drive torque against insert distance of the TIP into the
guide tubes.
DESCRIPTION OF THE EMBODIMENTS
[0021] Reference will now be made in detail to the present
embodiment of the invention, an example of which is illustrated in
the accompanying drawing. Wherever possible, the same reference
numbers will be used throughout the drawing to refer to the same or
like parts.
[0022] Referring to FIG. 1 of the drawing, in a reactor container
31, a reactor pressure vessel 33 is stabilized on a pedestal 32.
According to one exemplary embodiment, a TIP system 200 includes a
TIP drive unit 1, a probe cable 11, a TIP 12, a shielding vessel
21, an indexing device 22, guide tubes 23, and calibration tubes
24.
[0023] Furthermore, according to one exemplary embodiment, the TIP
drive unit 1 includes a housing 2, an introduction path 3, a
storage reel 4, a motor 5, a reduction gear 6, a control unit 7, a
processor 8, a motor controller 9, and a noise filter 13.
[0024] As shown FIG. 1, the housing 2 of the TIP drive unit 1 is
provided outside of the reactor container 31. The introduction path
3 penetrates the reactor container 31, and the introduction path 3
is connected to one side of the housing 2. In the housing 2, the
storage reel 4, the motor 5, and the reduction gear 6 are provided.
One edge of the probe cable 11 is connected to the storage reel 4,
and the storage reel 4 configured to storage the probe cable
11.
[0025] The motor 5 and the reduction gear 6 comprise a drive
mechanism so as to feed the probe cable 11 from the storage reel 4
and spool the probe cable 11 onto the storage reel 4 through the
introduction path 3 by rotating the storage reel 4.
[0026] The control unit 7 is connected to a central monitoring room
10 so as to receive a operation command 100 from a central
monitoring room 10. And the control unit 7 is connected to the
motor controller 9 so as to send a drive command 101 to the motor
controller 9. Furthermore, the control unit 7 is connected to the
indexing device 22 so as to send a indexing command 102 to the
indexing device 22. The motor controller 9 is connected to the
motor 5 so as to drive the motor 5 by supplying power.
[0027] The processor 8 is connected to the motor controller 9 so as
to receive drive information 110 from the motor controller 9.
Additionally, the processor 8 is connected to the central
monitoring room 10 so as to send torque information 111 to the
central monitoring room 10. The noise filter 13 is provided on a
sending path of information 110 from the motor controller 9 to
processor 8. The central monitoring room 10 is connected to the
probe cable 11 so as to receive a measured result of neutron flux
130 from the TIP 12 through the probe cable 11.
[0028] The opposite end of the probe cable 11 is connected to the
TIP 12. The shielding vessel 21 is provided inside of the reactor
container 31 and outside of the pedestal 32. The shielding vessel
21 stores and keeps the TIP 12 within. Additionally, the shielding
vessel 21 is communicated with the introduction path 3 so as to
move the probe cable 11 inside of the introduction path 3 and the
shielding vessel 21.
[0029] The indexing device 22 is provided outside of the pedestal
32 and inside of the shielding vessel 21. The indexing device 22 is
communicated with the shielding vessel 21 so as to move the probe
cable 11 and the TIP 12 inside of the shielding vessel 21 and the
indexing device 22.
[0030] Each guide tube 23 penetrates through the pedestal 32. And
the each guide tube 23 is communicated with the indexing device 22
so as to move the probe cable 11 and the TIP 12 inside of the
indexing device 22 and the each guide tube 23. Here, the
calibration tubes 24 provided in the reactor 33 vertically near the
LPRMs. Each guide tube 23 is communicated with the corresponding
calibration tube 24 so as to move the probe cable 11 and the TIP 12
into the calibration tubes 24 from the guide tubes 23.
[0031] Measuring neutron flux by using TIP system 200 is described
as follows. Ordinary, the TIP 12 is stored in the shielding vessel
21. In order to calibrate the sense of LPRMs, at the time of
measurement of neutron flux by TIP system 200, the central
monitoring room 10 sends the operation command 100 to the control
unit 7. The control unit 7 receives the operation command 100, and
divides the operation command 100 into the drive command 101 and
the indexing command 102. Furthermore, the control unit 7 sends the
drive command 101 to the motor controller 9, and sends the indexing
command 102 to the indexing device 22.
[0032] Here, the drive command 101 indicates predefined distance
and rotating speed of motor 5 while the TIP 12 and the probe cable
11 move in the guide tubes 23 and the calibration tubes 24. The
indexing command 102 indicates the guide tube 23 that the indexing
device 22 index the TIP 12 to the calibration tube 24 designated to
measure neutron flux.
[0033] The motor controller 9 receives the drive command 10 from
the control unit 7, and drives the motor 5 at predefined rotating
speed, and feeds the probe cable 11 through the introduction path 3
from the storage reel 4. The motor controller moves the TIP 12
stored in the shielding vessel 21 to the indexing device 22.
[0034] The indexing device 22 receives the indexing command 102
from the control unit 7, and index the TIP 12 to the guide tube 23
communicated with the calibration tube 24 designated to measure
neutron flux.
[0035] Furthermore, the motor controller 9 drives the motor 5 and
feeds the probe cable 11 from the storage reel 4, and the TIP 12
moves inside of the calibration tube 24 through the guide tube
23.
[0036] TIP 12 measures neutron flux near the LPRMs with moving
inside of the calibration tube 24, and sends the measured result of
neutron flux 130 to the central monitoring room 10 through the
probe cable 11. The central monitoring room 10 calibrates the
sensitivity of the LPRMs by using the measured result of neutron
flux 130.
[0037] After moving the TIP 12 to the predefined end point of
inside of the calibration tube 24, the motor controller 9 reverses
motor 5 and spools the probe cable 11 onto the storage reel 4, and
moves the TIP 12 back to the indexing device 22.
[0038] When the operation command 100 includes the command that
designate to measure neutron flux in other calibration tube 24, the
indexing device 22 indexes the TIP 12 to the other calibration tube
24, and the motor controller 9 moves the TIP 12 inside of other
calibration tube 24.
[0039] After moving of the TIP 12 in all designated calibration
tube 24, the motor controller 9 spools the probe cable 11 onto the
storage reel 4 and store the TIP 12 in the shielding vessel 21.
[0040] Next, calculating cable drive torque is described as
follows. Cable drive torque is torque necessary for feeding and
spooling the probe cable 11. The control unit 7 commands the motor
controller 9 to drive the motor 5 at predefined rotating speed
(.omega.) by using drive command 101.
[0041] Here, the motor controller 9 includes a monitoring feature
of load fluctuation. This feature monitors the rotating speed
(.omega.) and change supply power (W) so as to keep the predefined
rotating speed (.omega.). This monitoring feature probably applies
a method of monitoring the phase shifting of the supply power (W)
by a vector analysis.
[0042] Along with driving the motor 5 at predefined rotating speed
(.omega.) by drive command 101, the motor controller 9 sends the
value of rotating speed (.omega.) and supply power (W) per unit of
time such as 1 second and 10 seconds to the processor 8 as the
drive information 110.
[0043] In advance, the processor 8 memorizes loss-torque (T0),
which is torque necessary for driving the drive mechanism including
the motor 5 and the reduction gear 6 at predefined rotating speed
(.omega.).
[0044] The loss-torque (T0) increases in connection with arise of
rotating speed (.omega.), and decreases in connection with arise of
oil temperature in the motor 5. In advance, by doing experiment,
the values of loss-torque (T0) at various rotating speed (.omega.)
and oil temperature is measured, and the processor 8 memorize the
loss-torque (T0) as a function of rotating speed (.omega.) and oil
temperature.
[0045] At this point, all torque (T1), which is torque necessary
for driving the motor 5 and reduction gear 6 and for moving the TIP
12 and the probe cable 11, is indicated by the following formula
(1).
All torque (T1)=supply power (W)/rotating speed (.omega.) (1)
[0046] Moreover, cable drive torque (T2) that is a torque necessary
for moving the probe cable 11 and the TIP 12 in the guide tubes 23
is calculated by deriving from all torque (T1) by loss of loss
torque (T0). Thus, cable drive torque (T2) is indicated by the
following formula (2).
Cable drive torque (T2)=all torque (T1)-loss torque (T0) (2)
[0047] The processor 8 calculates the all torque (T1) by using the
drive information 110 and formula 1. In addition, the processor 8
calculate the cable drive torque (T2) per unit time by using the
value of rotating speed (w) of the motor 5, the loss torque (T0),
and formula 2. The processor 8 sends above calculated result, such
as the all torque (T1), the loss torque (T0), and the cable drive
torque (T2), to the central monitoring room 10 as torque
information 111.
[0048] As shown FIG. 2, along with inserting TIP 12 into the guide
tube 23, a contact area of the probe cable 11 and the guide tube 23
increase, and the all torque (T1) also increases. On the other
hand, the loss torque (T0) stays constant when the rotating speed
(.omega.) stays constant. Thus, regardless of position of TIP 12,
the cable drive torque (T2) is calculated by calculating the all
torque (T1) by formula 1, and subtracting the loss torque (T0) from
the all torque (T1).
[0049] The central monitoring room 10 receives cable drive torque
(T2) as the torque information 111, and homologize the cable drive
torque (T2) and a position of the TIP 12 and the probe cable 12
where the cable drive torque (T2) was measured on the basis of
drive command 100.
[0050] Furthermore, the central monitoring room 10 may be capable
of comparing the cable drive torque (T2) and a normal cable drive
torque. When the cable drive torque (T2) exceeds a normal range,
the central monitoring room 10 determines that lubricant fell away
and a large friction is occurred at the position where the cable
drive torque (T2) is measured.
[0051] Finally, the function of noise filter 13 is described as
follows. The measurement of neutron flux takes long time such as 2
hours, and the motor 5 starts, stops, rotates and reverses during
the measurement. Therefore, the motor 5 has a large torque capacity
in order to prevent performance decrement due to such as heat
generation in the motor 5.
[0052] Furthermore, the motor controller 9 includes an inverter so
as to drive the motor 5 at various speeds. And the inverter has a
plenty of electric capacity so as to spool the probe cable 11
during large friction situation like emergency. Thus, the inverter
has a lager electric capacity than necessary for the usual flux
measurement, and the motor controller 9 drives the motor 5 at lower
electricity than its maximum electric capacity.
[0053] Here, the motor 5 and the motor controller 9 generate noise,
typically the inverter of the motor controller 9 generates
high-frequency noise at operation.
[0054] In order to calculate the cable drive torque (T2), a signal
indicating the value of supply power (W) is amplified because the
supply power (W) is less than a maximum capacity of inverter and
the apparent fluctuation of the supply power (W) is small. When the
noise is mixed with the signal indicating value of supply power
(W), the noise is also amplified and the fluctuation of the signal
indicating the value of supply power (W) may hide amongst the
noise. In the result, it may be difficult to calculate fluctuation
of the cable drive torque (T2) by using the value of supply power
(W).
[0055] Therefore, the noise filter 13 is provided so as to remove
the noise, and the processor 8 calculates the cable drive torque
(T2) by using the value of supply power (W) that noise is
removed.
[0056] A low-pass filter configured to remove the high-frequency
noise generated from the inverter may be applied to the noise
filter 13. Furthermore, in cases where main noise is power-supply
frequency noise generated from the inverter, a low-pass filter
configured to remove a higher frequency signal than power-supply
frequency is probably provided to the noise filter 13. In addition,
the noise filter 13 may be also attached to the inside of the
inverter so as to remove noise from the inverter.
[0057] Additionally, in another embodiment, the TIP system 200 may
be modified as follows. By using the drive command 101, the motor
controller 9 may be capable of driving the motor 5 at high-speed
while the TIP 12 moves in the guide tube 23, and drives the motor 5
at low-speed while the TIP 12 moves in the calibration tube 24.
[0058] As shown FIG. 3, during high-speed moving the loss torque
(T0) is getting higher, and during low-speed moving the loss torque
(T0) is getting lower. Thus, processor 8 memorize the loss torque
(T0) in different rotating speed (.omega.) of motor 5, the
processor 8 may be capable of calculating the cable drive torque
(T2) while the TIP 12 moves at different speed.
[0059] According to this embodiment, the processor 8 may be capable
of calculating the cable drive torque (T2) stably by using rotating
speed (.omega.) of motor 5, the value of supply power (W) to the
motor 5, and loss torque (T0).
[0060] Furthermore, because the loss torque (T0) is considered as
an intrinsic value of rotating speed (.omega.), by memorizing loss
torque (T0) in different rotating speed (.omega.), the processor 8
may be capable of calculating the cable drive torque (T2) at
various rotating speed of the motor 5. In the result, amount time
of moving of the TIP12 at measurement of neutron flex whole is
saved, due to high-speed moving in the guide tube 12.
[0061] Furthermore, by providing the noise filter 13, the processor
8 may be capable of calculating the cable drive torque by using the
signal that the noise is removed.
[0062] At this point, in order to apply this embodiment to an
existing TIP system, the processor 8 is additionally provided so as
to receive the value of rotating speed (.omega.) and supply power
(W). In the result, it does not need to open the housing 2 storing
the probe cable 11 radioactibated, and an explosion of utility
workers is decreased.
[0063] Other embodiments of the invention will be apparent to those
skilled in the art from consideration of the specification and
practice of the invention disclosed herein. It is intended that the
specification and examples be considered as exemplary only, with a
true scope and spirit of the invention being indicated by the
following claims.
[0064] For example, the setting position of the TIP drive unit 1,
the indexing device 22, and guide tubes 23 may be changed by a
design basis and demand of nuclear power plant.
[0065] Furthermore, the drive mechanism feeding and spooling the
probe cable 11 is not only comprised by the motor 5 and the
reduction gear 6. For example, a component that the motor 5 is
attached to a central shaft of the storage reel 4 directly may be
applied to the drive mechanism.
[0066] Still furthermore, the loss torque (T0) is not only
determined as the function of rotation speed (.omega.) and the oil
temperature. For example, the loss torque (T0) may be determined
additionally by parameter of aging degradation of the motor 5 and
the oil. And the loss torque (T0) may be determined as a function
of the rotation speed (.omega.) or the oil temperature only.
* * * * *