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H. Yan et al.
and online detection. Open tank inspection is a method to detect the bottom plate of
the tank after the tank is shut down and cleaned by using the macro, magnetic leakage,
thickness measurement and other non-destructive testing methods. Due to the process
of tank opening detection, such as shutdown and tank cleaning, this method will
require a lot of manpower, material and financial resources. Relevant statistics show
that at present, only 9% of the open tanks do have serious corrosion or leakage, and
the open tank detection of other tanks has different degrees of waste. In view of
the problems such as high cost of open tank maintenance, serious over time storage
tank, and severe impact of imported crude oil with low oil price on tank corrosion,
it is urgent to detect and evaluate the tank with a fast and online detection method.
With the popularization and application of acoustic emission detection technology
in the corrosion detection of the bottom plate of atmospheric storage tank, more and
more atmospheric storage tanks first use acoustic emission detection technology to
classify and grade the bottom plate, and then select the targeted open tank detection
according to the rating results. This method greatly overcomes the time-consuming
caused by blind open tank detection such as shutdown replacement, cleaning the
bottom of the tank, point by point scanning inspection Lack of effort [1, 2].
The so-called acoustic emission is the phenomenon of transient elastic waves
generated by the rapid release of energy from local sources in materials, also known
as stress wave emission or micro vibration activity [3, 4]. In an ideal situation,
the acoustic emission detection of the bottom plate of atmospheric storage tank is
to use the acoustic receiving sensor arranged at a certain height from the bottom
plate to receive the corrosion signal from the bottom plate, and use the coaxial
cable to transmit the acoustic signal from the receiving sensor to the data processing
center. The processing center positions and correlates the collected signal according
to a certain calculation method, and finally gives different correlation results. The
inspector grades the results according to relevant standards, determine the corrosion
condition of the bottom plate of the tank to be inspected, and put forward reasonable
maintenance strategies. However, when using AE online detection, a lot of noise will
seriously affect the acquisition, analysis and discrimination of real signals, such as
wind and rain will affect the acquisition of signals; vibration and electromagnetic
interference will affect the analysis and discrimination of signals. For light oil and
volatile, flammable and explosive media, the corresponding nitrogen sealing system
is often used on the top of the tank during storage, which can not only prevent
the top of the tank from emitting combustible gas, but also prevent the air from
entering the tank, forming an explosion [5–7]. Nitrogen sealing system can effectively
reduce the volatilization of organic gases and prevent the pollution of toxic gases
to the surrounding environment. However, if nitrogen sealing system is used, noise
interference caused by pressure change will occur when nitrogen is replenished. If
this interference source cannot be effectively prevented or eliminated in the detection,
the detection result will not reflect the real situation of the tested object, so that how
to effectively reduce is the key to obtain effective and real acoustic emission data for
the impact of noise of nitrogen sealing system on the test results. In this paper, the
acoustic emission detection system based on three-point positioning algorithm is used
to detect the on-line acoustic emission of atmospheric tank with nitrogen seal system
H. Yan et al.
and online detection. Open tank inspection is a method to detect the bottom plate of
the tank after the tank is shut down and cleaned by using the macro, magnetic leakage,
thickness measurement and other non-destructive testing methods. Due to the process
of tank opening detection, such as shutdown and tank cleaning, this method will
require a lot of manpower, material and financial resources. Relevant statistics show
that at present, only 9% of the open tanks do have serious corrosion or leakage, and
the open tank detection of other tanks has different degrees of waste. In view of
the problems such as high cost of open tank maintenance, serious over time storage
tank, and severe impact of imported crude oil with low oil price on tank corrosion,
it is urgent to detect and evaluate the tank with a fast and online detection method.
With the popularization and application of acoustic emission detection technology
in the corrosion detection of the bottom plate of atmospheric storage tank, more and
more atmospheric storage tanks first use acoustic emission detection technology to
classify and grade the bottom plate, and then select the targeted open tank detection
according to the rating results. This method greatly overcomes the time-consuming
caused by blind open tank detection such as shutdown replacement, cleaning the
bottom of the tank, point by point scanning inspection Lack of effort [1, 2].
The so-called acoustic emission is the phenomenon of transient elastic waves
generated by the rapid release of energy from local sources in materials, also known
as stress wave emission or micro vibration activity [3, 4]. In an ideal situation,
the acoustic emission detection of the bottom plate of atmospheric storage tank is
to use the acoustic receiving sensor arranged at a certain height from the bottom
plate to receive the corrosion signal from the bottom plate, and use the coaxial
cable to transmit the acoustic signal from the receiving sensor to the data processing
center. The processing center positions and correlates the collected signal according
to a certain calculation method, and finally gives different correlation results. The
inspector grades the results according to relevant standards, determine the corrosion
condition of the bottom plate of the tank to be inspected, and put forward reasonable
maintenance strategies. However, when using AE online detection, a lot of noise will
seriously affect the acquisition, analysis and discrimination of real signals, such as
wind and rain will affect the acquisition of signals; vibration and electromagnetic
interference will affect the analysis and discrimination of signals. For light oil and
volatile, flammable and explosive media, the corresponding nitrogen sealing system
is often used on the top of the tank during storage, which can not only prevent
the top of the tank from emitting combustible gas, but also prevent the air from
entering the tank, forming an explosion [5–7]. Nitrogen sealing system can effectively
reduce the volatilization of organic gases and prevent the pollution of toxic gases
to the surrounding environment. However, if nitrogen sealing system is used, noise
interference caused by pressure change will occur when nitrogen is replenished. If
this interference source cannot be effectively prevented or eliminated in the detection,
the detection result will not reflect the real situation of the tested object, so that how
to effectively reduce is the key to obtain effective and real acoustic emission data for
the impact of noise of nitrogen sealing system on the test results. In this paper, the
acoustic emission detection system based on three-point positioning algorithm is used
to detect the on-line acoustic emission of atmospheric tank with nitrogen seal system