Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment
The article presents the results of an experimental study relevant to the effective organization of temperature control of thermomechanical equipment at nuclear power plants (turbines, pumps, steam generators, deaerators, etc.). Bench studies of the reaction of the DS18B20 digital intelligent temper...
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| Cite this: | Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment / Y.M. Bikovsky, O.V. Derevianko, V.V. Levchenko, A.Y. Pogosov // Problems of atomic science and tecnology. — 2020. — № 4. — С. 98-106. — Бібліогр.: 20 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1944232025-02-23T17:26:44Z Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment Імітаційні дослідження роботи цифрового датчика температури при нестандартній механічній дії обладнання АЕС Имитационные исследования работы цифрового датчика температуры при нестандартном механическом воздействии оборудования АЭС Bikovsky, Y.M. Derevianko, O.V. Levchenko, V.V. Pogosov, A.Y. Diagnostics and methods of researches The article presents the results of an experimental study relevant to the effective organization of temperature control of thermomechanical equipment at nuclear power plants (turbines, pumps, steam generators, deaerators, etc.). Bench studies of the reaction of the DS18B20 digital intelligent temperature sensor, which is supposed to be introduced at Ukrainian nuclear power plants, to the application of external compression force to its body, which may occur under conditions typical for the operation of equipment operating at nuclear power plants, have been carried out. An electrical circuit diagram has been developed for a reset signal simulation device (for bench modeling of a sensor application system). The issues of identifying a sign in the sensor output signal informing about the effect of an external compression force on its body are considered. The technique of bench experiments and processing of research results necessary to address the issue of introducing new digital measuring equipment for temperature control of thermomechanical equipment of nuclear power plants is given. Представлено результати експериментального дослідження, актуального для ефективної організації контролю температури тепломеханічного обладнання на АЕС (турбін, насосів, парогенераторів, деаераторів та ін.). Проведено стендові дослідження реакції цифрового інтелектуального датчика температури DS18B20, передбачуваного до впровадження на АЕС України, на дію зовнішньої сили стиснення на його корпус, яка може виникнути в умовах, характерних для експлуатації діючого на АЕС обладнання. Розроблена електрична принципова схема пристрою імітації сигналу «скидання» (для стендового моделювання системи застосування датчика). Розглянуто питання виявлення у вихідному сигналі датчика ознаки, що інформує про вплив зовнішньої сили стиснення на його корпус. Наведено методику проведення стендових експериментів та обробки результатів досліджень, необхідних для вирішення питання про впровадження нових цифрових засобів вимірювальної техніки для контролю температури тепломеханічного обладнання АЕС. Представлены результаты экспериментального исследования, актуального для эффективной организации контроля температуры тепломеханического оборудования на АЭС (турбин, насосов, парогенераторов, деаэраторов и др.). Проведены стендовые исследования реакции цифрового интеллектуального датчика температуры DS18B20, предполагаемого к внедрению на АЭС Украины, на приложение внешней силы сжатия на его корпус, которая может возникнуть в условиях, характерных для эксплуатации действующего на АЭС оборудования. Разработана электрическая принципиальная схема устройства имитации сигнала «сброс» (для стендового моделирования системы применения датчика). Рассмотрены вопросы выявления в выходном сигнале датчика признака, информирующего о воздействии внешней силы сжатия на его корпус. Приведена методика проведения стендовых экспериментов и обработки результатов исследований, необходимых для решения вопроса о внедрении новых цифровых средств измерительной техники для контроля температуры тепломеханического оборудования АЭС. 2020 Article Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment / Y.M. Bikovsky, O.V. Derevianko, V.V. Levchenko, A.Y. Pogosov // Problems of atomic science and tecnology. — 2020. — № 4. — С. 98-106. — Бібліогр.: 20 назв. — англ. 1562-6016 https://nasplib.isofts.kiev.ua/handle/123456789/194423 621.039; 81.2.08; 621.311.25 en Вопросы атомной науки и техники application/pdf Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
Diagnostics and methods of researches Diagnostics and methods of researches |
| spellingShingle |
Diagnostics and methods of researches Diagnostics and methods of researches Bikovsky, Y.M. Derevianko, O.V. Levchenko, V.V. Pogosov, A.Y. Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment Вопросы атомной науки и техники |
| description |
The article presents the results of an experimental study relevant to the effective organization of temperature control of thermomechanical equipment at nuclear power plants (turbines, pumps, steam generators, deaerators, etc.). Bench studies of the reaction of the DS18B20 digital intelligent temperature sensor, which is supposed to be introduced at Ukrainian nuclear power plants, to the application of external compression force to its body, which may occur under conditions typical for the operation of equipment operating at nuclear power plants, have been carried out. An electrical circuit diagram has been developed for a reset signal simulation device (for bench modeling of a sensor application system). The issues of identifying a sign in the sensor output signal informing about the effect of an external compression force on its body are considered. The technique of bench experiments and processing of research results necessary to address the issue of introducing new digital measuring equipment for temperature control of thermomechanical equipment of nuclear power plants is given. |
| format |
Article |
| author |
Bikovsky, Y.M. Derevianko, O.V. Levchenko, V.V. Pogosov, A.Y. |
| author_facet |
Bikovsky, Y.M. Derevianko, O.V. Levchenko, V.V. Pogosov, A.Y. |
| author_sort |
Bikovsky, Y.M. |
| title |
Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment |
| title_short |
Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment |
| title_full |
Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment |
| title_fullStr |
Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment |
| title_full_unstemmed |
Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment |
| title_sort |
simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the npp equipment |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2020 |
| topic_facet |
Diagnostics and methods of researches |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/194423 |
| citation_txt |
Simulation study of the digital temperature sensor operation in case of a non-standard mechanical impact of the NPP equipment / Y.M. Bikovsky, O.V. Derevianko, V.V. Levchenko, A.Y. Pogosov // Problems of atomic science and tecnology. — 2020. — № 4. — С. 98-106. — Бібліогр.: 20 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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2025-11-24T03:05:43Z |
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2025-11-24T03:05:43Z |
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| fulltext |
ISSN 1562-6016. PASТ. 2020. №4(128), p. 98-106.
UDC 621.039; 81.2.08; 621.311.25
SIMULATION STUDY OF THE DIGITAL TEMPERATURE SENSOR
OPERATION IN CASE OF A NON-STANDARD MECHANICAL IMPACT
OF THE NPP EQUIPMENT
Y.M. Bikovsky
1
,
O.V. Derevianko
1
, V.V. Levchenko
2
, A.Y. Pogosov
1
1
Odessa National Polytechnic University, Odessa, Ukraine
E-mail: bym.evrika@gmail.com, ov_derevianko@ukr.net, pogosov@ukr.net;
2
Zaporizhzhya NPP, Energodar, Ukraine
E-mail: levmaster77@gmail.com,
The article presents the results of an experimental study relevant to the effective organization of temperature
control of thermomechanical equipment at nuclear power plants (turbines, pumps, steam generators, deaerators,
etc.). Bench studies of the reaction of the DS18B20 digital intelligent temperature sensor, which is supposed to be
introduced at Ukrainian nuclear power plants, to the application of external compression force to its body, which
may occur under conditions typical for the operation of equipment operating at nuclear power plants, have been
carried out. An electrical circuit diagram has been developed for a reset signal simulation device (for bench
modeling of a sensor application system). The issues of identifying a sign in the sensor output signal informing
about the effect of an external compression force on its body are considered. The technique of bench experiments
and processing of research results necessary to address the issue of introducing new digital measuring equipment for
temperature control of thermomechanical equipment of nuclear power plants is given.
INTRODUCTION
At the enterprises of the nuclear energy industry
during the operation of technological equipment there
are various negative factors affecting the operation of
measuring instruments used to monitor technological
processes. These factors can lead to an increase in the
random component of the error of the measurements
taken in industrial operation. Factors of negative
influence on certain sensors by electromagnetic fields
that occur at nuclear power plants can be largely
eliminated by shielding measuring instruments and
transmitting measuring signals: the use of protective
covers, various types of insulation, etc. However, it is
impossible to get rid of some factors, including
mechanical influences among them, so you have to
make corrections to the measuring signals or use more
“rough” measurement results, which reduces the
reliability of the information received (that is,
information received from the measuring equipment in
the form of signals).
At present, analog thermal sensors installed in metal
sockets are still widely used at Ukrainian nuclear power
plants, which, for example, under transient operating
conditions of a power unit, under temperature changes,
undergo temperature stresses and deformations or, in
emergency situations, experience mechanical effects
negatively affecting the sensors load. Structurally, the
thermoresistors and thermocouples traditionally used at
nuclear power plants as analog primary measuring
transducers are strong enough to protect their sensitive
elements from external mechanical influences, but they
are significantly inferior in their operational
characteristics (in accuracy and noise immunity of the
signal) to digital temperature sensors (i.e. sensors with
digital output signals), considered as an additional
means of information support for the work of power
engineering, which in the near future should be
integrated into computer control systems for
technological equipment of nuclear power plants [1–3].
This circumstance is largely decisive in the issues of re-
equipping energy production with modern digital
measuring devices – that is, the strategy for the
transition from analog measuring instruments to digital
should be based on comprehensive preliminary studies
of the proposed measuring instruments for
implementation.
However, there are factors that significantly limit the
possibilities of upgrading temperature channels at
nuclear power plants and, first of all, they include the
almost complete absence of objective (that is, based on
bench experimental studies) information on the
operability of digital temperature sensors proposed for
implementation in nuclear energy production in non-
specific for them (conditions not assumed during the
development (based on the nameplate characteristics) -
namely, under conditions of mechanical stress on the
body. At the same time, the transition to digital
processing of measuring signals is becoming
increasingly important in nuclear power plants [4].
Some of the alleged limitations with regard to
intelligent digital temperature sensors, among which the
DS18B20 should be highlighted, include the completely
unexplored effect of mechanical pressure on their
housing and the influence of mechanical vibrations
(except for the obvious effects of magnetic and radiation
fields), the manifestations of which are characteristic of
the technological process conversion of thermal energy
into mechanical (and then electrical) at a nuclear power
plant. This circumstance determines the relevance of
this kind of research for nuclear energy in Ukraine
[5, 6].
In general, the relevance of the research is also
associated with the current trend of transition to digital
methods of transmitting primary measuring signals [7].
mailto:bym.evrika@gmail.com
mailto:pogosov@ukr.net
An analysis of literary sources shows that one of the
most significant destabilizing factors in the operation of
any digital sensor in operating conditions at nuclear
power plants is the mechanical effect on its body [8, 9].
This fully applies to temperature sensors used to
monitor the condition of materials in nuclear power
engineering. However, without specially organized
studies, it is not possible to predict the behavior of a
digital sensor located in the zone of influence of this
factor. In particular, in the accompanying
documentation of the sensor manufacturer (Dallas
Semiconductor, which is the leading provider of digital
sensors in the world market), this information is
completely absent.
At the nuclear power plant, various
thermomechanical equipment is used, the monitoring of
the state of materials of which is increasingly carried
out using digital measuring equipment. At the same
time, the cyclic redundancy check code CRC (Cyclic
redundancy check) is widely used – an algorithm that
provides for checking the checksum of elements of a
digital signal (0 and 1), designed to monitor data
integrity in a measuring signal. CRC is a common
practical error-correcting coding software application
for checking the reliability of transmitted signal
information, but this code does not take into account the
influence of external negative factors. Therefore, when
the end device (data processing system) receives a
distorted signal from the primary sensor and is guided
only by checking the standard CRC code, the user
(operator) may receive false (false) information about
the processes under study or not at all if the code does
not match the expected one.
An analysis of the publications [10, 11] suggests that
the effect of the compression force on its body remains
an unexplored issue of the effect on temperature
sensors.
The main goal of this work is to analyze the
technological behavior of the digital (intelligent,
algorithmically processing information) DS18B20
temperature sensor under the influence of mechanical
factors inherent in nuclear power facilities. In this
regard, the task arose to experimentally determine how
an increase in the compression force of the body of the
digital thermal sensor will affect the measuring ability
of the converter, taking into account the need for its use
to monitor the state of materials at nuclear power plants.
It was also necessary to find out – if such a factor
affects, then to what extent is this influence acceptable
in terms of the reliability and accuracy of the received
measuring signal. In addition to those presented above,
the question of the limits of the susceptibility of the
DS18B20 to external compression of the sensor housing
also remained open. The solution to these problems is a
continuation of our research that preceded this, the
results of which were published earlier [12–15].
1. CONDUCTING EXPERIMENTS
Since one of the most effective destabilizing
factors during the operation of a digital temperature
sensor in nuclear power plants is mechanical impact,
studying the limits of the susceptibility of sensors to
workloads of this type will take into account the
influence of this factor when modernizing the
measuring channels.
Considering the fact that there is no complete
information on the strength and signal-mechanical
characteristics of the DS18B20 sensor in the literature,
this object was presented in the form of a “black box”
with unknown properties: as you know, this is a
method of researching an object, when instead of the
properties and interconnections of its components, the
reaction of the object, as a whole, to changing
conditions is studied [16]. And, first of all, the issue of
identifying the sign of the sensor’s response (an
indicator of its sensitivity to external influences) to the
force applied to the body was resolved.
In Fig. 1 shows a photo of the investigated sensor.
It has three conclusions, only one of which is
informational, and is intended for receiving
(transmitting) signals (it was this conclusion that was
used as a channel for receiving information, depending
on the external mechanical effect on the sensor). As
follows from the technical description of the MicroLan
network [17], the information management computer
system interacts with the sensor via a digital
communication channel through this information
output sequentially, therefore, under the conditions of
the task, it is the only source of information about the
sensor status [18].
Fig. 1. Appearance of the temperature sensor DS18B20
A laboratory experiment was prepared taking into
account the following. The process of interaction
between the computer used in the research (a
microcontroller can also be used as such a control and
analytical device) with sensors located in the digital
signal input line consists in sequentially transmitting
requests and commands from the computer to the line
and receiving answers from identified ones (using
individual 64-bit codes) of the number of sensors
connected to the computer.
The duration of each individual measurement cycle
is about 750 ms, during which a large amount of
information is transmitted, including temperature
values, type of sensor, individual serial number, CRC
code and control commands. An analysis of a signal of
such a duration to solve the problem poses certain
difficulties in a bench experiment (high speed of
information exchange between a PC and a sensor, as
well as a large amount of analyzed information).
Therefore, the experimental technique provided for
minimizing the information capacity of the signal
under study, taking into account the fact that each
measurement cycle begins with sending an
initialization (reset) pulse from the PC to the line in
the form of a voltage drop (UOUT = 0) with a duration
of about 480 μs. If the line contains a serviceable and
ready for information exchange sensor, then after a
while it already sends its response to the computer side
in the form of a voltage drop, lasting from 60 μs to
240 μs (Fig. 2).
Fig. 2. Graphic illustration of the sensor initialization process
After the sensor response, the PC-sensor signal
exchange phase begins. Since in a complex two-way
signal it is fundamentally difficult to single out the
sensor responses that are of interest to us, the
experimental technique provides for taking into account
only the first of them formed during the initialization
process. The research methodology included physical
modeling of this process, which was carried out using a
device, a diagram of which is shown in Fig. 3.
Fig. 3. Electrical circuit diagram of the device simulating the signal “reset”
(for bench simulation of the sensor)
In the above diagram, an anti-bounce trigger is
assembled on the elements DD1.1 and DD1.2, the input
of which is supplied either manually (by pressing the
SB1 button) or from a functional generator selected by
the switch SA1. The one-shot at the elements DD1.3
and DD1.4 generates a reset pulse, the duration of
which can vary over a wide range by the resistor R3.
The output stage of the circuit through the resistor R5
provides a pull-up of the signal line of the sensor to a
level of plus 5 V in the pauses between pulses of
information exchange.
To conduct an experimental (bench) study of the
sensor reaction using the device described above, static
pressure was applied to its body from two sides, as
shown in Fig. 4. From technological considerations (for
the operating conditions of the NPP processing
equipment), the most likely direction of mechanical
action on the sensor body, is the impact shown in Fig.
4,a, characteristic, for example, in the case of pressing
the sensor to the surface of the measurement object to
reduce vibration and better contact with the surface of
the equipment, but this does not exclude the possibility
of exposure as shown in Fig. 4,b.
Fig. 4. Scheme of loading the temperature sensor
“from above” (a) and “side” (b)
For the experiment, the sensor was connected to a
digital oscilloscope, which is part of the computer
equipment of the stand for studying the operation of the
sensor.
The sequence of implementation of each research act
within the framework of the experiment provided for the
following procedures:
– application of mechanical force to the sensor
housing;
– formation of a “reset” impulse (using the
developed scheme);
– registration and saving of the sensor output signal
(using a digital oscilloscope);
Communication
phase
Reset pulse Answer
PC Sensor
> 480 s 60…240 s
15…60 s
a b
– analytical processing of the signal received from
the sensor (as a reaction to the applied force).
In Fig. 5 shows, on an enlarged scale, the graphs of
the trailing edge of the sensor response pulse (see also
Fig. 2) under the influence of force in two directions
taken during the design of the experiment.
The leading edge of the pulse, as shown by
experiments, practically did not change in time and,
therefore, was not considered by us. The sensor was
subjected to an increasing effect of force until it was
mechanically destroyed – the experiment was
terminated in the absence of an output signal from the
sensor. The influence of the vibration factor (i.e.
dynamic loads) in the described series of experiments
was not studied.
Fig. 5. Trailing edge of the signal from the sensor
The results of the experiments indicate a change in
the pulse duration of the sensor signal (“communication
phase”) at the same mechanical pressure on the housing
depending on the direction of the applied force. It was
also found that the directions of the displacement of the
trailing edge of the pulse in both cases differ
significantly.
An analysis of the experimental data leads to the
understanding that these differences are due to the
topologies of the placement of the crystal in the sensor
body (and the corresponding natural frequencies of its
vibrations) and, accordingly, different manifestations of
deformation effects depending on the direction of
compression of the body. In both cases considered, the
sensor signal returned to its initial state when the
external mechanical effect was removed, which
indicates the absence of the “memory” effect, which
means that it allows monitoring the trends in the
external effect on the sensor during temperature control.
This circumstance can be used for diagnostic purposes
(in addition to obtaining temperature data at the place of
installation of the sensor) - to determine the directions
of deformation in the material of equipment where such
a sensor will be installed.
Since the results shown in Fig. 5 were estimates
(qualitative from the point of view of the feasibility of
using the sensor at nuclear power plants), they were
used as a basis (basis) for expanding the program of
experiments. Further bench studies were carried out to
determine the quantitative limits of the mechanical load
on the sensor and were carried out by changing the
forces from different sides from 0 N to a value at which
the sensor was completely destroyed.
At the same time as conducting the experiment on
mechanical compression, temperature measurements
were carried out using standard temperature measuring
instruments that were not subjected to mechanical
stresses to detect differences in the readings of an
independent sensor (describe this as an independent
sensor) and the test one.
3. ANALYSIS OF RESULTS
Fig. 6 shows a graph of the displacements of the
trailing edge of the sensor signal when the pressure
changes to the “upper” face of its body (Fig. 4,a).
The graphs show a pronounced tendency to decrease
the pulse duration with increasing effort.
To analyze the results presented graphically and to
obtain functional approximating dependencies, the
mathematical apparatus of regression analysis was used
as a method for assessing the influence of independent
variables (parameters) associated with an object on a
dependent parameter, which allows to correlate cause
and effect.
So, it was taken into account that, in practice, the
dependencies between two random variables, which are
represented by the results of their repeated observations,
are most often studied [19,20]:
{ }
{ }
(1)
In the presence of a correlation between the random
variables X and Y, a functional dependence Y = F(X)
takes place.
As is known, the mathematical apparatus of
regression analysis suggests that the values of xi and yi
are mutually independent and normally distributed.
80 82 84 86 88 90 92 94 t, s
t, mks
0.6
1.2
1.8
2.4
3.0
3.6
4.2
0
U, V
Effortless
Lateral force
After removing the effort
Rectangular Force
Fig. 6. The offset of the trailing edge of the sensor signal
Due to the fact that it was not possible to select an
elementary analytical function that adequately describes
the experimental data, regression using a polynomial
was applied to obtain a mathematical model of the
process under consideration.
The regression equation can be represented as
a polynomial of degree k:
∑
,
(2)
where Bi – coefficients of the regression equation, which
were found by the least squares method.
The optimal value of the degree of the polynomial k
is found by sequential refinement (an increase in the
value of k, starting from k = 1). The degree of the
polynomial is optimal if it provides the smallest value of
the residual dispersion Dk (the dispersion due to the
scatter of experimental points around the regression
line). In other words, a sequential increase in k ensures
that the approximating curve approaches the
experimental points (i.e., reduces the residual
dispersion) until the optimal value of k is reached, after
which its further increase either does not change the
dispersion or leads to its increase .
The residual dispersion was determined by the
formula
∑
, (3)
where n – is the number of experimental points;
y'i = f (xi) – values of Y calculated by the regression
equation; (xi, y'i) – the coordinates of the experimental
points.
The initial analysis led to the conclusion that in our
case, with this regression equation, at each step of
refining the degree of the polynomial, it is necessary to
recalculate all Bi coefficients. Therefore, it was decided
to simplify the calculations by writing the regression
equation using Chebyshev polynomials Pi(x):
∑
.
(4)
Chebyshev polynomials of the first and second
orders have the form:
(5)
̅
∑
(6)
Chebyshev polynomial of arbitrary order Pi (x) can
be found knowing the polynomials of the two previous
orders Pi-1(x) и Pi-2(x):
(7)
∑
∑
(8)
∑
∑
, (9)
where Pi-1(xj), Pi-2(xj) – Chebyshev polynomials at the
points xj (calculated by substituting the results of
observations xj into polynomials).
Moreover, the coefficients of the regression equation
are found by the formula:
∑
∑
. (10)
Thus, at each step of refining the degree of the
polynomial k, only one coefficient was calculated using
the well-known formula, which reduced the amount of
calculations and simplified the methodology for
analyzing the experimental results. In addition, the
calculations of the residual variance were simplified,
since there was no need to calculate the regression
residues.
The value of Dk was found by the formula:
(11)
80 78 74 72 70 t, s 76
1.2
2.4
3.6
4.8
U, V 0 N
100 N
200 N
300 N
400 N
500 N
600 N
700 N
800 N
900 N
1000 N
1100 N
1200 N
1300 N
1400 N
∑
∑
(12)
∑
(13)
In the case of applying the force to the sensor “from
above” (see Fig. 4,a) as a result of the calculations
performed during the analysis, the following results
were obtained.
The regression equation for k = 1 is obtained in the
form:
.
(14)
The value of the residual dispersion was:
;
;
.
Since D2<D1 and D2<D3, the second-order
regression equation, as we can conclude, more
accurately describes the experimental data than the
third-order regression equation and, taking into account
the above, is thus optimal for the analytical description
the results obtained.
Thus, the dependence of the response time of the
sensor on the magnitude of the applied mechanical load,
in the case of pressure on the rectangular face of the
sensor:
. (15)
The results of studies of the sensor response under
mechanical action on its lateral face (see Fig. 4,b) are
shown in Fig. 7.
Fig. 7. Displacement of the trailing edge of the sensor signal with increasing force on the side face
As experimental studies have shown, the mechanical
effect in the lateral direction turned out to be more
dangerous for the sensor than in the previous case - such
an effect led to its destruction even with an impact force
of 400 N.
The function that describes the dependence of the
sensor response pulse duration on the magnitude of the
force applied to its lateral face, determined by the
analysis method considered above, has the form:
(16)
During the experiment, a similar DS18B20 sensor
was used as a reference temperature sensor (blue curve),
the metrological characteristics of which were checked
using an ATC-156B reference temperature calibrator.
The second temperature sensor was subjected to force
(red curve), dashed lines show the maximum
permissible absolute values of the temperature sensor
± 0.5 °С. Shown in fig. The curves 8 and 9 made it
possible to analyze the change in the standard output
signal of the temperature sensor under study for various
directions of the force applied to its body.
As can be seen from Fig. 8, the planar mechanical
effect (on a flat face) is practically not detected by the
electronic measuring circuit in any way up to a force of
400 N. At the same time, the detected information sign
(the duration of the sensor response pulse) overcame
almost half of its maximum change (see Fig. 6), which
indicates its high stability.
The impact on the side face of the sensor began to be
reflected in its output signal even with small changes in
force (Fig. 9). As can be seen from Figs. 8 and 9, the
value of the basic absolute error exceeds the permissible
limits of ± 0.5 °C, declared by the manufacturer. This
circumstance should be taken into account, because
receiving false information about the flow of the
technological process at nuclear power plants is
unacceptable.
124 122 120 118 114 112 126 t, s 116 128
1.2
0
2.4
3.6
4.8
U, V
0 N
100 N
200 N
300 N
400 N
Fig. 8. Graph of the output signal of the temperature sensor at change of pressure “from above”
Fig. 9. Graph of the output signal of the temperature sensor when changing the pressure “side”
4. THE DISCUSSION OF THE RESULTS
As a result of the studies, experimental confirmation
of the assumption of the influence of mechanical force
on the shape of the output signal was obtained. The
dependences of the sensor output signal on the amount
of applied force are determined. This is important for
understanding the possibilities of using in the conditions
of work at nuclear power plants in order to prevent
erroneous notification of operators about the presence of
a malfunction (i.e., a deviation in the technological
system or process), which may require corrective action
on the part of the operator.
The results can be used to conduct further research
(to determine the operability of the sensor in the event
of vibration or ionizing radiation) or to decide on the
use of sensors in nuclear power plants based on the
obtained experimental data. "
Empirically, an information sign was identified that
allows you to timely remotely detect the presence of
mechanical pressure on the sensor housing without the
need for access to it.
Experimental studies of the remotely controlled
reaction of the temperature sensor were carried out, with
the application of force to its body. When conducting
bench experiments, it was found that under the action of
compression forces up to 1350 N (when exposed as
shown in Fig. 4,a) and up to 60 N (when exposed as
shown in Fig. 4,b) the temperature readings of the
sensor practically coincide with the control data
(reference) thermometer located next to the probe under
study. This indicates the stability of the digital sensor
and, undoubtedly, refers to its advantages. However, a
further increase in the force on the sensor by only 30 N
(in the first case) and 10 N (in the second case) distorted
the output signal. This can be considered as an
information sign of the achievement of a dangerous
limit of mechanical impact on the sensor - that is, as a
sign by which it is possible to judge the fact of
achievement by force of a level, exceeding which
signals the unreliability and inexpediency of further
accounting of measurement results. The basis for such a
judgment is that, after exceeding the force of the
indicated level, the physical destruction of the
measuring transducer occurred, which showed the
limitations of the use of the sensor for temperature
monitoring on equipment capable of mechanical
deformation.
The described approach to the processing of the
output signal can be performed in real time to prevent
the formation of alarms using false information arising
from failures of the sensors generating the output
signals.
CONCLUSIONS
One of the issues of using a digital temperature
sensor to control the technological process of nuclear
power plants was considered: the effect of increasing
the compression force on the housing of the DS18B20
sensor, planned for use at nuclear power plants, at least
on the equipment of a steam turbine installation. Bench
experimental studies were conducted, the results of
which revealed the permissible limits of the parameters
0 150 300 450 600 750 900 1050 1200
21
21.5
22
22.5
23
23.5
24
t
t1
v
n
F
T, ℃
24
23.5
23
22.5
22
21.5
21
0 150 300 450 600 750 900 1050 F, N
1200 F, N
Reference sensor
The test sensor
0 50 100 150 200 250 300 350 400
21
21.5
22
22.5
23
23.5
24
t
t1
v
n
F
0 50 100 150 200 250 300 350 F, N
400 F, N
T, ℃
24
23.5
23
22.5
22
21.5
21
Reference sensor
The test sensor
of mechanical action on digital temperature sensors
planned for implementation at nuclear power facilities,
which allows us to expand the program of further
research aimed at the scientific support of
modernization of control systems for monitoring the
condition of materials in nuclear power engineering
equipment.
The ultimate goal of bench experiments and
mathematical modeling, provided that the sensors under
consideration are put into operation of NPPs, can be the
creation of appropriate software and hardware systems
as elements of expert systems to support the operator of
nuclear energy facilities and other industrial enterprises
whose technological process requires temperature
control.
The results obtained in the course of an experimental
study can narrow the range of problems in the field of
atomic science and technology in terms of adequate
monitoring of the temperature of the power equipment
of nuclear power plants using computerized digital
measuring instruments.
REFERENCES
1. M.Yu. Okhtilev, B.V. Sokolov, R.M. Yusupov.
Intelligent technologies for monitoring and controlling
the structural dynamics of complex technical objects.
M.: “Nauka”, 2006, 410 p.
2. V.B. Trofimov, S.M. Kulakov. Intelligent
automated systems for managing technological objects
// International Journal of Experimental Education.
2016, N 12 (part 1), p. 113.
3. J.F. Canete. System Engineering and
Automation: Interactive Educational Approach
Springer. 2011, 268 p.
4. NS-G-1.3 IAEA Safety Standards Series.
Instrumentation and control systems important to the
safety of nuclear power plants. Guide.
5. S.P. Gubarev, A.V. Leonovich, R.M.Muratov,
Y.N. Nezovibatko, G.P. Opaleva, V.S. Taran,
M.I. Zolototrubova Hardware-software complex for
automated control and monitoring of the vacuum system
of the BULAT-6 installation // PAST. 2019, N 1(119),
p. 135-137.
6. V.S. Osadchuk et al. Influence of pressure on the
parameters of semiconductor structures: Naukovі pracі
VNTU, 2009, N 1, p. 1-5.
7. IEC 62241:2004 Nuclear power plants Main
control room Alarm functions and presentation.
8. IEC 62262: 2002 Degrees of protection provided
by enclosures for electrical equipment against external
mechanical impacts (IK code).
9. DS18B20. Technical description.
10. A.Yu. Pogosov, O.V. Derevyanko. Metro-
logical support of NPP operation. Odessa: “Science and
technology”, 2016, 204 p.
11. I. Gertsbakh, Y. Shpungin. Network Reliability.
Springer, 2020, 95 p. (Springer Briefs in Electrical and
Computer Engineering).
12. Yu.M. Bykovsky, V.V. Levchenko. On the
assessment of the possibility of using digital sensors in
temperature measurement channels at Ukrainian NPPs:
Sat scientific works of SNUYaEiP N 3(35), 2010,
280 p.
13. Yu.M. Bikovskiy, V.V. Levchenko, O.Yu. Po-
gosov. Experimental testing of the influx of
electromagnet fields on digital temperature sensors with
single-mouth lines for monitoring the operation of AIC
systems in AEC control systems // Nuclear and
Radiation Free Shop. 2019, N 2(82).
14. V.V. Levchenko, Y.M. Bykovsky, O.Y. Pogo-
sov. New possibilities of application of digital
measuring transducers for control of temperature fields
at the stage of decommissioning of NPP power units
and monitoring of the state of the environment //
Problems of decommissioning of nuclear power
facilities and environmental restoration (INUDECO
19): Proceedings of the IV International Conference
April 2019, Slavutych). Chernihiv: ChNTU, 2019,
p. 136-146.
15. A.Yu. Pogosov, V.V. Levchenko, Yu.M. Bi-
kovsky. Analysis of Prospects for Application of
Intellectual Digital Temperature Sensors in Data
Channels of On-Line Control Means at Nuclear Power
Plants // Material of Conference IEEE (ESS) (17–19 April
2019, Kyiv, Ukraine) p. 76-79.
16. V.N. Volkova, A.A. Denisov. Theory of
systems and system analysis: a textbook for bachelors.
M.: “Publishing House Yurayt”; ID Jurayt, 2012, 679 p.
17. MicroLAN network interface [Electronic
resource]. - Access mode:
http://icmicro.narod.ru/info_ru/microlan/microlan.htm.
18. 1-Wire and iButton datasheet.
19. Handbook of Applied Statistics. In 2 volumes:
Per. with English / Ed. E. Lloyd, W. Lederman,
Y.N. Tyurina. M.: “Statistics”, 2009, 510 p.
20. I.F. Stefan. Mathematical methods of
experimental data processing. Kemerovo: GUKuzGTU,
2008.
Article received 21.07.2020
ИМИТАЦИОННЫЕ ИССЛЕДОВАНИЯ РАБОТЫ ЦИФРОВОГО ДАТЧИКА
ТЕМПЕРАТУРЫ ПРИ НЕСТАНДАРТНОМ МЕХАНИЧЕСКОМ ВОЗДЕЙСТВИИ
ОБОРУДОВАНИЯ АЭС
Ю.М. Быковский, О.В. Деревянко, В.В. Левченко, А.Ю. Погосов
Представлены результаты экспериментального исследования, актуального для эффективной организации
контроля температуры тепломеханического оборудования на АЭС (турбин, насосов, парогенераторов,
деаэраторов и др.). Проведены стендовые исследования реакции цифрового интеллектуального датчика
https://ieeexplore.ieee.org/author/37086914243
https://ieeexplore.ieee.org/author/37086914243
https://ieeexplore.ieee.org/author/37086915017
https://ieeexplore.ieee.org/author/37086915017
http://icmicro.narod.ru/info_ru/microlan/microlan.htm
температуры DS18B20, предполагаемого к внедрению на АЭС Украины, на приложение внешней силы
сжатия на его корпус, которая может возникнуть в условиях, характерных для эксплуатации действующего
на АЭС оборудования. Разработана электрическая принципиальная схема устройства имитации сигнала
«сброс» (для стендового моделирования системы применения датчика). Рассмотрены вопросы выявления в
выходном сигнале датчика признака, информирующего о воздействии внешней силы сжатия на его корпус.
Приведена методика проведения стендовых экспериментов и обработки результатов исследований,
необходимых для решения вопроса о внедрении новых цифровых средств измерительной техники для
контроля температуры тепломеханического оборудования АЭС.
ІМІТАЦІЙНІ ДОСЛІДЖЕННЯ РОБОТИ ЦИФРОВОГО ДАТЧИКА ТЕМПЕРАТУРИ
ПРИ НЕСТАНДАРТНІЙ МЕХАНІЧНІЙ ДІЇ ОБЛАДНАННЯ АЕС
Ю.М. Биковський, О.В. Дерев’янко, В.В. Левченко, А.Ю. Погосов
Представлено результати експериментального дослідження, актуального для ефективної організації
контролю температури тепломеханічного обладнання на АЕС (турбін, насосів, парогенераторів, деаераторів
та ін.). Проведено стендові дослідження реакції цифрового інтелектуального датчика температури DS18B20,
передбачуваного до впровадження на АЕС України, на дію зовнішньої сили стиснення на його корпус, яка
може виникнути в умовах, характерних для експлуатації діючого на АЕС обладнання. Розроблена
електрична принципова схема пристрою імітації сигналу «скидання» (для стендового моделювання системи
застосування датчика). Розглянуто питання виявлення у вихідному сигналі датчика ознаки, що інформує про
вплив зовнішньої сили стиснення на його корпус. Наведено методику проведення стендових експериментів
та обробки результатів досліджень, необхідних для вирішення питання про впровадження нових цифрових
засобів вимірювальної техніки для контролю температури тепломеханічного обладнання АЕС.
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