CN109060962B

CN109060962B - Device for testing relative hardness of settled layers with different heights in crude oil storage tank and application thereof

Info

Publication number: CN109060962B
Application number: CN201810922661.8A
Authority: CN
Inventors: 黄启玉; 孙旭; 李文欣; 林福贺; 赵旗
Original assignee: China University of Petroleum Beijing
Current assignee: China University of Petroleum Beijing
Priority date: 2018-08-14
Filing date: 2018-08-14
Publication date: 2020-10-27
Anticipated expiration: 2038-08-14
Also published as: CN109060962A

Abstract

The application provides a device for testing the relative hardness of sediment layers with different heights in a crude oil storage tank and application thereof, wherein the device comprises a first container for filling sediment samples of the crude oil storage tank; the mobile testing assembly is detachably arranged outside the side wall of the first container and comprises a guide rail, carrying equipment capable of moving along the guide rail and an ultrasonic probe arranged on the carrying equipment; when the mobile testing component is arranged outside the side wall of the crude oil storage tank to be tested, the carrying equipment can be close to the side wall of the crude oil storage tank and can move vertically along the guide rail, and the ultrasonic probe can transmit ultrasonic signals to the crude oil storage tank and receive corresponding reflected signals. On one hand, the device can be used for acquiring the hardness conditions of the settled layers with different heights in the operating storage tank; on the other hand, the hardness data measured by the device and the physical properties and wax dissolving conditions of the crude oil obtained by the crude oil sedimentation and stratification experimental device are combined, so that the start-stop time of the stirrer in the crude oil storage tank can be reasonably predicted, and the operation parameters can be more effectively adjusted.

Description

Device for testing relative hardness of settled layers with different heights in crude oil storage tank and application thereof

Technical Field

The invention belongs to the field of oil storage, and particularly relates to a device for testing the relative hardness of settled layers with different heights in a crude oil storage tank and application thereof.

Background

Petroleum is an important strategic energy source of China, 9 national petroleum reserve bases including Zhoushan, Zhoushan extension, Zhenhai, Dalian, Huangdao, Dushan, Lanzhou, Tianjin and Huangdao national petroleum reserve caverns are built in China at present, and the national petroleum reserve capacity is estimated to be improved to about 8500 million tons in 2020. The petroleum can form a deposit layer at the bottom of the storage tank in the long-term storage process, and the deposit layer not only can reduce the effective volume of the storage tank, but also can block an oil inlet pipeline and an oil outlet pipeline to cause environmental pollution. Along with the increasing of global oil demand, the proportion occupied by imported crude oil and unconventional oil is more and more, the oil source and quality are unstable, the impurity condition in the oil is greatly different, and the conditions of tank bottom sediment layers are different due to the difference of oil properties and storage environment.

The crude oil storage tank is cleaned once in 3-6 years generally, a tank bottom stirrer is adopted to prevent oil sludge from depositing in the operation process, the stirrer is arranged in the tank and is directly connected with an oil inlet of the storage tank, the power of the stirrer comes from outside the tank area, the operation is safe and reliable, the construction is simple and easy, no shaft sealing part exists, and oil leakage pollution is avoided. Common stirring modes include tank wall fixed nozzle stirring, tank center fixed nozzle stirring, rotating nozzle stirring and the like, and the stirring modes are also used for oil product blending in the tank. The crude oil is a mixture composed of low molecular hydrocarbons, wax, colloid, asphaltene and the like, and colloidal particles (wax, asphaltene and fine silt) are mutually adsorbed in the standing storage process of the crude oil in the storage tank, so that the quality and the size are continuously increased, the crude oil is accumulated and settled, and a deposition layer is formed at the bottom of the tank. The storage period of the strategic reserve of petroleum is long, the external disturbance is less, the deposition layer can be repeatedly dissolved and recrystallized along with the lapse of time, so that the deposition layer becomes more hardened, and the content of the colloid, asphaltene and other heavy components is higher as the content is closer to the content of the tank bottom, which shows that the hardness of the deposition is gradually increased from top to bottom. The sediment with high hardness not only increases the working strength of the tank bottom jet stirrer, but also can block an oil inlet pipeline and an oil outlet pipeline in serious conditions, thereby affecting the oil receiving and dispatching operation and causing serious production accidents of the storage tank.

However, it is difficult for personnel to obtain the hardness of the deposit in the tank during operation of the tank.

Disclosure of Invention

The purpose of this specification is to provide a device for testing the relative hardness of sediment layers with different heights in a crude oil storage tank and an application thereof, wherein the device can acquire the hardness condition of the sediment layers with different heights in an operating storage tank.

To achieve the above objects, in one aspect, the present specification provides an apparatus for testing relative hardness of deposits at different heights in a crude oil storage tank, the apparatus comprising:

a first vessel for filling a crude oil storage tank sediment sample;

a mobile testing assembly removably mounted to an exterior of the first container sidewall, the mobile testing assembly comprising: a guide rail; a carriage movable along the rail; the ultrasonic probe is arranged on the carrying equipment; a first controller for controlling movement of the vehicle; and a second controller for controlling the operation of the ultrasonic probe;

when the mobile testing component is detachably arranged outside the side wall of the first container, the ultrasonic probe can be close to the outer wall of the first container to transmit ultrasonic signals and receive corresponding reflected signals;

when the mobile testing component is detachably arranged outside the side wall of the crude oil storage tank to be tested, the carrying equipment can be close to the side wall of the crude oil storage tank and vertically move along the guide rail, and the ultrasonic probe can transmit ultrasonic signals to the crude oil storage tank and receive corresponding reflected signals.

In the above apparatus for testing the relative hardness of a sediment layer of a crude oil storage tank, preferably, the mobile testing assembly further comprises a pressing member for adjusting or maintaining the ultrasonic probe in close proximity to the outer wall of the first container and/or the side wall of the crude oil storage tank.

In the above apparatus for testing the relative hardness of the crude oil storage tank sediment layer, preferably, the guide rail comprises two parallel slide rails; the carrying equipment is arranged between the two slide rails in a spanning mode, and a through hole used for accommodating the ultrasonic probe is formed in the carrying equipment body; the pressing piece is arranged above the through hole; the ultrasonic probe is accommodated in the through hole, and the distance between the ultrasonic probe and the side wall of the first container and/or the side wall of the crude oil storage tank can be adjusted through the pressing piece.

In the above apparatus for testing the relative hardness of the sediment layer of the crude oil storage tank, preferably, the material of the side wall of the first container is the same as that of the side wall of the crude oil storage tank.

In another aspect, the present description provides a method of adjusting the operation of a blender in a crude oil storage tank, the method comprising:

measuring the relative hardness data of the sediment layers with different heights in the crude oil storage tank to be measured by adopting the device; dividing a sedimentary layer of the crude oil storage tank to be detected into a plurality of height intervals, and taking the average value of relative hardness data in the height intervals as the hardness of the height intervals;

preparing a first experimental sample in a crude oil sedimentation layering experimental device; the first experimental sample comprises a sedimentary deposit simulation sample and an oil product simulation sample; the sedimentary deposit simulated sample comprises at least one sedimentary sublayer, and the hardness of the sedimentary sublayer is close to the hardness of a certain height interval of a sedimentary deposit in the crude oil storage tank to be detected; the oil product simulation sample is an oil product taken from a crude oil storage tank to be detected or an oil sample prepared by referring to the oil product; the crude oil sedimentation layering experimental device is a device capable of researching the dissolution condition of the sedimentary deposit simulation sample in the oil product simulation sample under the stirring condition; obtaining dissolution data of the sedimentary stratum simulation sample in the oil product simulation sample corresponding to different stirring conditions through the crude oil sedimentation and stratification experimental device;

and adjusting the start-stop time and/or the operation parameters of the stirrer in the crude oil storage tank according to the dissolution data.

In the above method for adjusting the operation of a stirrer in a crude oil storage tank, preferably, the sediment sub-layer is a sediment sample representing different hardness for a bottom sediment and an oil product preparation configuration in the crude oil storage tank to be measured.

In the above method for adjusting the operation of the stirrer in the crude oil storage tank, preferably, the sediment layer simulation sample comprises at least two sediment sublayers for simulating two adjacent height intervals in the sediment layer in the crude oil storage tank to be measured.

In the above method of adjusting the operation of a stirrer in a crude oil storage tank, preferably, the dissolution data includes physical property data or wax dissolution data of the oil simulant.

In the above method of adjusting the operation of a blender in a crude oil storage tank, preferably, the physical property data includes density, congealing point or viscosity.

In the above method of adjusting the operation of a blender in a crude oil storage tank, preferably, the method further comprises: calculating flow field distribution data of the deposition layer simulation sample in the container in the stirring process by a large vortex simulation method according to the dissolution data; and further combining the flow field distribution data to adjust the start-stop time and/or the operation parameters of the stirrer in the crude oil storage tank.

In the above method of adjusting the operation of a blender in a crude oil storage tank, preferably, the step of obtaining relative hardness data for sediment layers of different heights comprises:

preparing sediment samples representing different hardness by using the bottom sediment and oil in the crude oil storage tank to be detected; taking the hardness of the bottom sediment sample as the standard hardness, and obtaining respective relative hardness data of other sediment samples by taking the standard hardness as the standard hardness;

acquiring the transmission speed of the ultrasonic waves in each sediment sample by using the mobile testing component, wherein the transmission speed is recorded as a first speed, and the set of the transmission speed and the first speed forms a first speed set;

loading all sediment samples into the first container, and then acquiring the transmission speed of ultrasonic waves in sediment layers with different heights of the crude oil storage tank to be tested by using the mobile testing component, wherein the transmission speed is recorded as a second speed, and the transmission speed and the second speed form a second speed set;

and comparing the second speed set with the first speed set to find out the first speed closest to each second speed, wherein the relative hardness corresponding to the first speed is the relative hardness data of the height deposition layer.

In the above method for adjusting the operation of the stirrer in the crude oil storage tank, preferably, the crude oil sedimentation and stratification experiment apparatus comprises:

a tank for storing oil;

an oil inlet pipeline arranged on the tank body;

the settlement data testing component is arranged on the tank body and comprises at least one group of testing units; the test unit comprises an online viscometer and an online particle analyzer which are arranged on the same horizontal plane of the tank body;

the sampling ports are arranged on the tank body, and the arrangement positions and the number of the sampling ports correspond to the horizontal positions and the number of the test units;

the stirring device is arranged in the tank body;

and the oil drainage port is arranged at the bottom of the tank body.

In the above method for adjusting the operation of the stirrer in the crude oil storage tank, preferably, the tank body is externally provided with a water jacket interlayer for heating the tank body.

In the above method of adjusting the operation of a blender in a crude oil storage tank, preferably, the blending means comprises at least one fixed nozzle and/or rotating nozzle.

In the above method of adjusting the operation of a stirrer in a crude oil storage tank, preferably, the fixed nozzle is provided on the inner wall of the tank body and in the center of the tank body; the rotary nozzle is arranged in the center of the tank body.

In the solution provided in the present specification, on one hand, the device for testing the relative hardness of the sediment layers with different heights in the crude oil storage tank has a good correlation between the propagation speed of the ultrasonic wave in the sediment and the hardness thereof, and on the basis, the transmission speed of the ultrasonic wave in the sediment layer samples with different hardness, that is, the first speed, can be obtained through the cooperation of the first container and the mobile testing component; then, the mobile testing component is arranged at a sediment layer outside the crude oil storage tank to be tested, and the transmission speed of the ultrasonic waves in the sediment layers with different heights, namely a second speed, can be obtained through continuous measurement; and comparing the first speed with the second speed, and correlating the first speed with the relative hardness data of the sedimentary deposit sample so as to obtain the relative hardness of the sedimentary deposit with different heights. On the other hand, the hardness data measured by the device and the dissolving data of the sedimentation layer simulation sample in the oil product simulation sample under different stirring conditions, which is obtained by the crude oil sedimentation layer experimental device, can be combined to more effectively adjust the start-stop time and/or the operation parameters of the stirrer in the crude oil storage tank.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for assisting the understanding of the present application, and are not particularly limited to the shapes, the proportional sizes, and the like of the respective members in the present application. Those skilled in the art, having the benefit of the teachings of this application, may select various possible shapes and proportional sizes to implement the present application, depending on the particular situation. In the drawings:

FIG. 1a is a front view of a mobile testing assembly in one embodiment of the present description;

FIG. 1b is a top view of the mobile testing assembly of the embodiment of FIG. 1 a;

FIG. 1c is a side view of the mobile testing assembly of the embodiment of FIG. 1 a;

FIG. 2 is a schematic diagram of a relative hardness testing apparatus for testing a sample of a deposited layer in one embodiment of the present disclosure;

FIG. 3a is a schematic structural diagram of a crude oil sedimentation stratification experimental apparatus in one embodiment of this specification;

FIG. 3b is a cross-sectional view of a portion of the reservoir in the embodiment of FIG. 3 a;

FIG. 4 is a schematic diagram illustrating the installation of a stirrer in the crude oil settling and stratifying experimental apparatus according to one embodiment of the present disclosure;

FIG. 5a is a schematic structural view of a fixed nozzle of a tank wall according to an embodiment of the present disclosure;

FIG. 5b is a schematic diagram of a fixed center nozzle of a canister according to one embodiment of the present disclosure;

FIG. 5c is a schematic view of a rotary nozzle in one embodiment of the present disclosure;

FIG. 6 is a graph showing the dissolution rate of blank crude oil with different properties to bottom sediment in Experimental example 2 as a function of wax content;

FIG. 7 is a graph showing the dissolution rate of blank crudes of different properties in experimental example 2 for bottom sediments as a function of viscosity;

FIG. 8 is a graph of viscosity as a function of shear rate for # 1 blank crude oil in Experimental example 2 after incorporation into a bottoms deposit;

FIG. 9 is a graph of viscosity as a function of shear rate for # 2 blank crude oil in Experimental example 2 after incorporation into a bottoms deposit;

FIG. 10 is a graph of viscosity as a function of shear rate for experimental example 2# blank crude oil blended into a bottoms deposit;

FIG. 11 is a graph of viscosity as a function of shear rate for # 4 blank crude oil in Experimental example 2 after incorporation into a bottoms deposit;

the reference numbers illustrate:

101-a guide rail; 102-a carrier device; 103-ultrasonic probe; 104-a compression member;

1-a top cover; 2-insulating layer; 3-an online particle sizer; 4-a centrifugal pump; 5-a turbine flow meter; 6-hydraulic regulating valve; 7-a nozzle; 8-water jacket interlayer; 9-a hose; 10-program-controlled water bath; 11-in-line viscometer; 12-an oil drainage port; 13-a base; 14-a sampling port; 15-a scaffold; 16-tank outer flange a; 17-in-can flange B; 18-can internal flange C.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In one aspect, in one embodiment of the present description, an apparatus for testing the relative hardness of sediments at different heights in a crude oil storage tank comprises:

a first vessel for filling a crude oil storage tank sediment sample;

a mobile testing assembly (see fig. 1a, 1b, 1c) removably mountable to an exterior of a sidewall of the first container, the mobile testing assembly comprising: a guide rail 101; a carrier device 102 movable along the guide rail; an ultrasonic probe 103 provided on the carrier device 102; a first controller (not shown in fig. 1a-1 c) for controlling the movement of the vehicle; and a second controller (not shown in figures 1a-1 c) for controlling operation of the ultrasound probe;

when the mobile testing component is detachably mounted on the outer portion of the side wall of the first container, the ultrasonic probe 103 can be close to the outer wall of the first container to emit ultrasonic signals and receive corresponding reflected signals;

when the mobile testing component is detachably mounted on the outer portion of the side wall of the crude oil storage tank to be tested, the carrying equipment can be close to the side wall of the crude oil storage tank and can vertically move along the guide rail 101, and the ultrasonic probe 103 can transmit ultrasonic signals to the crude oil storage tank and receive corresponding reflected signals.

The hardness of the sediment is an important factor affecting the dissolution and it is therefore difficult to anticipate and adjust the operation of the blender in the crude oil storage tank in situations where the hardness of the sediment in the tank is not available, so that the operation of the blender in the tank can often only be determined empirically. First, in this case, the empirical adjustment often fails to achieve the desired treatment effect once some sudden condition affecting the sedimentation occurs in the storage period, and in this case, for the sake of safety, it is only possible to increase the operation power of the agitator or to extend the agitation time, or to shorten the start-up interval of the agitator. However, this results in a significant waste of energy and excessive consumption of the stirring equipment, which is difficult for the oil storage enterprises to endure for a long time. Secondly, because the hardness change condition of the sediments in the storage tank cannot be detected in the prior art, the excessive hardening trend of the sediments cannot be found in time, and the excessive hardening sediments are difficult to be effectively dissolved after the stirring is started according to experience. At the moment, the treatment can be carried out only by oil discharge and manual treatment, so that the treatment difficulty and the treatment cost are greatly increased. Thirdly, because the hardness of the sediment in the storage tank is different at different heights, and the difference is difficult to predict (especially, some environment mutation situations can be met in the long-time sedimentation process), the operation of the stirrer can only be adjusted comprehensively, and the adjustment effect cannot be reduced according to the actual situation.

The embodiment provided by the specification particularly designs a device for testing the relative hardness of sedimentary layers with different heights in a crude oil storage tank, and successfully solves the problems in the prior art. The scheme is designed on the basis of verifying that the propagation speed of the ultrasonic wave in the sediment has good correlation with the hardness of the sediment. Specifically, the transmission speed of the ultrasonic waves in the settled layer samples with different hardness, namely a first speed, can be obtained through the cooperation of the first container and the mobile testing component; then, the mobile testing component is arranged at a sediment layer outside the crude oil storage tank to be tested, and the transmission speed of the ultrasonic waves in the sediment layers with different heights, namely a second speed, can be obtained through continuous measurement; and comparing the first speed with the second speed, and correlating the first speed with the relative hardness data of the sedimentary deposit sample so as to obtain the relative hardness of the sedimentary deposit with different heights.

In the above embodiment, the first container is provided as a columnar container, but is not limited thereto, and may be other conventional shapes. In addition, it is preferable to use a container having the same thickness of both side walls. In some embodiments of the present description, the first vessel is a small steel vessel with a diameter of 100mm and a wall thickness of 10 mm.

In the above embodiment, after the first container is filled with the sediment sample, the carrying device does not need to be started during the test, and the ultrasonic probe is controlled to work by the second controller; when the mobile testing component is used for testing the storage tank to be tested, the carrying equipment is required to work while the ultrasonic probe works because the mobile testing component needs test data with different heights.

In the above embodiments, as for the manner in which the mobile testing assembly is mounted on the first container or the tank to be tested, a conventional means in the art may be employed as long as the guide rail can be fixed to the outer wall of the first container or the tank to be tested. For example, adhesive or straps may be used.

In the above embodiments, the "vertical movement" of the carrying device relative to the crude oil storage tank is the movement perpendicular to the bottom of the tank, generally parallel to the meridian of the tank. The ultrasonic transmission speed data of the sediment layers with different heights can be obtained in the mode, the carrying equipment is loaded with the ultrasonic probe and runs along the sliding rail, the measured data can be continuous, and errors of manual operation can be reduced.

Referring to fig. 2, in some embodiments of the present description, it may be arranged to acquire mainly the following paths of the ultrasonic signals: the signal firstly passes through the side wall at the near end of the probe, secondly passes through the sediment layer, secondly passes through the side wall at the far end of the probe, finally forms reflection at the side wall and the air interface, returns along the original path, and is received by the ultrasonic probe again. The reflected signal of the path is strong, and is convenient to identify and obtain; also, other reflected signals may be excluded by suitable means.

In some embodiments of the present disclosure, in order to facilitate the calculation of the ultrasonic transmission speed during the test, the material of the sidewall of the first container may be the same as the material of the sidewall of the crude oil storage tank.

Referring to fig. 1a-1c, in some embodiments of the present description, the mobile testing assembly further comprises a compression member 104, the compression member 104 being configured to adjust or maintain the ultrasonic probe 103 in close proximity to a sidewall of the first vessel and/or a sidewall of the crude oil storage tank. In some embodiments of the present description, a probe that can detect a distance between the ultrasonic probe and a sidewall of the first vessel or a sidewall of the crude oil storage tank may also be provided on the carrier; of course, the distance of the probe from the side wall of the first container or the side wall of the crude oil storage tank can also be tested directly by means of an ultrasonic probe via a suitable control module.

With continuing reference to fig. 1a-1c, in some embodiments of the present description, the mobile testing component may be configured to: the guide rail 101 comprises two parallel slide rails; the carrying device 102 spans between the two slide rails, and a through hole for accommodating the ultrasonic probe 103 is arranged on the body of the carrying device 102; the pressing piece 104 is arranged above the through hole; the ultrasonic probe 103 is received in the through hole and is adjustable in distance from the side wall of the first container and/or the side wall of the crude oil storage tank by the pressing member 104.

With continued reference to fig. 1a-1c, in some embodiments of the present disclosure, the carrier device 102 is a carrier cart with four wheels, and the slide rail has a concave straight groove for receiving the wheels of the carrier cart; the carrying trolley is provided with a motor for driving the trolley to move, and the power supply of the motor is provided by a battery carried by the motor.

In some embodiments of the present disclosure, a first controller is configured to control the movement of the carrying device, and a second controller is configured to control the operation of the ultrasound probe. The first controller and the second controller can be corresponding control modules of a control center (computer); the control center can be connected with the trolley and the ultrasonic probe through a data line and sends out corresponding instructions.

In the above embodiments, after the relative hardness data of the deposition layers with different heights are measured by the apparatus, the actual hardness data can be obtained by a conventional measurement or comparison method, and therefore, the actual hardness data is not described in detail in the embodiments of the present specification.

In another aspect, in a method of adjusting operation of a blender in a crude oil storage tank in an embodiment of the present description, the method includes:

s1: measuring the relative hardness data of the sediment layers with different heights in the crude oil storage tank to be measured by adopting the device; dividing a sedimentary layer of the crude oil storage tank to be detected into a plurality of height intervals, and taking the average value of relative hardness data in the height intervals as the hardness of the height intervals;

s2: preparing a first experimental sample in a crude oil sedimentation layering experimental device; the first experimental sample comprises a sedimentary deposit simulation sample and an oil product simulation sample; the sedimentary deposit simulation sample comprises at least one sedimentary sublayer, and the hardness of the sedimentary sublayer is close to the hardness of a certain height interval of a sedimentary deposit in the crude oil storage tank to be detected; the oil product simulation sample is an oil product taken from a crude oil storage tank to be detected or an oil sample prepared by referring to the oil product; the crude oil sedimentation layering experimental device is a device capable of researching the dissolution condition of a sedimentary deposit simulation sample in an oil product simulation sample under a stirring condition;

s3: obtaining the dissolution data of the sedimentary stratum simulation sample in the oil product simulation sample corresponding to different stirring conditions through a crude oil sedimentation layering experimental device;

s4: and adjusting the start-stop time and/or the operation parameters of the stirrer in the crude oil storage tank according to the dissolution data.

In the above embodiment, after the relative hardness data of the sediment layers with different heights in the crude oil storage tank is obtained, the dissolution condition of the corresponding sediment layers under different stirring conditions can be researched on the basis of the relative hardness data, so that the problem that the dissolution condition of the sediment in the storage tank cannot be researched by combining the hardness distribution data in the prior art is solved.

In the above embodiment, the agitation dissolution state in a certain height section may be studied by the sedimentation stratification experimental apparatus alone, or the agitation dissolution state in a plurality of height sections or all height sections may be studied. In the sedimentation delamination experiment, the thickness of the deposition sublayer can be determined and adjusted through a certain conversion ratio, and is not required to be set according to the thickness of the height interval in the actual storage tank. In some preferred embodiments, the sediment layer simulation sample comprises at least two sediment sublayers for simulating two adjacent height intervals in the sediment layer in the crude oil storage tank to be tested.

In some embodiments of the present description, the sediment sub-layer can be configured to represent sediment samples of different hardnesses for the bottom sediment and the oil in the crude tank under test. For conventional tanks, the bottom sediment is relatively easy to obtain, while other locations of the sediment are more difficult to obtain samples that meet the experimental volume. On one hand, the structural design of the storage tank determines the difficult acquirability of samples at other parts; on the other hand, due to the limitations of the sampling equipment, the target sample is easily disturbed by the non-target deposit. Therefore, it is difficult to study the hardness of the deposit layer by sampling, or the measured hardness data is often deviated from the actual situation. On the basis of acquiring the hardness of the deposition layers with different heights through ultrasonic waves, the embodiment provided by the specification can further utilize the bottom layer deposition to configure a sample with the hardness close to that of the deposition of the storage tank to be detected (the hardness of the configured sample can be detected and confirmed through a mobile testing component of the device), so that the research on the dissolution condition of the deposition layer has higher reliability in the embodiment. In some embodiments of the present disclosure, in order to more fully study the stirring and dissolution of the deposit layer, the dissolution can be determined by obtaining physical property data, wax dissolution data, and other parameters of the oil simulation sample during stirring. In some embodiments, the physical property data includes density, congealing point or viscosity, and the like.

In some embodiments of the present description, the flow field distribution data of the deposition layer simulation sample in the container during the stirring process can be calculated by a large vortex simulation method; and further combining the flow field distribution data to adjust the start-stop time and/or the operation parameters of the stirrer in the crude oil storage tank. Combining the calculation method, the stirring and the dissolving condition of the settled layer can be studied more deeply.

In some embodiments of the present specification, in the step of S1, the step of acquiring relative hardness data of the deposition layers of different heights includes:

s101: preparing sediment samples representing different hardness by using the bottom sediment in the crude oil storage tank to be detected and crude oil; taking the hardness of the bottom sediment sample as the standard hardness, and obtaining respective relative hardness data of other sediment samples by taking the standard hardness as the standard hardness;

s102: acquiring the transmission speed of the ultrasonic waves in each sediment sample by using a mobile testing assembly, wherein the transmission speed is recorded as a first speed, and the set of the transmission speed and the first speed forms a first speed set;

s103: filling all sediment samples into the first container, and then acquiring the transmission speed of ultrasonic waves in sediment layers with different heights of the crude oil storage tank to be detected by using the mobile testing component, wherein the transmission speed is recorded as a second speed, and the transmission speed and the second speed form a second speed set;

s104: and comparing the second speed set with the first speed set to find out the first speed closest to each second speed, wherein the relative hardness corresponding to the first speed is the relative hardness data of the height deposition layer.

In some embodiments of the present description, the process of obtaining the first speed through the steps S101 and S102 specifically includes:

(1) installing the mobile testing component outside the side wall of the first container, enabling the ultrasonic probe to work through the second controller, and obtaining the transmission time of the sound wave in the single-layer tank wall of the container, which is recorded as t_{Container with a lid}

(2) Respectively taking crude oil and bottom sediment from a crude oil storage tank to be detected, and configuring sediment samples representing different hardness by using the crude oil and the bottom sediment; taking the hardness of the bottommost sediment sample as a benchmark hardness, and taking the standard hardness of other sediment samples as a standard to obtain respective relative hardness data, and recording the relative hardness data as Ym (m represents the volume percentage of the bottommost sediment in the sample, and m is more than or equal to 0% and less than or equal to 100%);

(3) respectively loading sediment samples with different hardness into a first container, and obtaining a first parameter under the samples, wherein the first parameter is the propagation time required by the ultrasonic wave to pass through the outer wall at the measuring point to reach the outside of the opposite side wall of the measuring point and then return according to the original path and is recorded as Tm;

(4) binding t_{Container with a lid}Tm and the diameter of the first vessel, the propagation velocity Vm of the ultrasonic wave in the sediment sample of the hardness is calculated and is recorded as a first velocity.

In some embodiments of the present description, the process of obtaining the second speed through the step S103 specifically includes:

(1) installing a mobile testing component at a position corresponding to a deposition layer on the outer side of the side wall of the crude oil storage tank, enabling the carrying equipment to move along the guide rail through a first controller, and enabling the ultrasonic probe to work through a second controller so as to obtain a second parameter; the second parameter is the propagation time Tx (x represents the height of the measuring point relative to the bottom of the tank body, namely the thickness of the sediment) required by the ultrasonic wave to return along the original path after passing through the outer wall at the measuring point to the outside of the opposite side wall of the measuring point;

(2) and calculating the propagation speed Vx of the ultrasonic wave at the height sediment layer according to Tx, and recording the propagation speed Vx as a second speed.

Referring to fig. 3a and 3b, in some embodiments of the present disclosure, a crude oil sedimentation stratification experimental apparatus capable of acquiring crude oil physical properties and wax dissolution in real time may be used in S3, and the apparatus includes:

a tank for storing oil;

an oil inlet pipeline arranged on the tank body;

the settlement data testing component is arranged on the tank body and comprises at least one group of testing units; the testing unit comprises an online viscometer 11 and an online particle analyzer 3 which are arranged on the same horizontal plane of the tank body;

the sampling ports 14 are arranged on the tank body, and the arrangement positions and the number of the sampling ports 14 correspond to the horizontal positions and the number of the test units;

the stirring device is arranged in the tank body;

and an oil drain port 12 arranged at the bottom of the tank body.

In the device, the real-time acquisition of crude oil physical properties and wax dissolving conditions can be realized by simultaneously arranging the on-line viscometer and the on-line particle size analyzer at the same height. The start and stop time of the stirrer can be better predicted and adjusted through the acquired data, and the specific operation parameters during stirring can be reasonably adjusted.

Referring to fig. 3a and 3b, in some embodiments of the present disclosure, the tank body is cylindrical and has an oil storage cavity, the oil storage cavity can hold oil required by an experiment, an outer cylinder is disposed outside the oil storage cavity, an annular cavity is formed between the oil storage cavity and the outer cylinder, and circulating water can be injected into the annular cavity. Specifically, a water jacket interlayer 8 is arranged outside the tank body, and the water jacket interlayer 8 is communicated with a program control water bath 10 through a hose 9, so that the temperature in the tank body is controlled. In some embodiments of the present description, the temperature control range of the programmable water bath 10 is from-80 ℃ to 200 ℃.

In some embodiments of the present disclosure, the tank body is made of stainless steel, which has high corrosion resistance. The height of the tank body is 125cm, and the inner diameter of the oil storage tank is 50 cm.

With continued reference to fig. 3a and 3b, in some embodiments of the present description, a top cover 1 is provided on the top of the tank body, and an insulating layer 2 may be provided outside the water jacket interlayer 8. The filler of the heat preservation layer 2 can be a chemical cross-linked polyethylene foam material, the tensile strength is high, the foam holes are fine, the heat conductivity coefficient is low, and the temperature of the crude oil in the oil storage tank can be fully guaranteed not to be influenced by the external environment.

With continued reference to fig. 3a and 3b, one skilled in the art can install the necessary valves and lines in the crude oil settling stratifying assay device as desired. In some embodiments, the valves are all ball valves, the caliber of each ball valve is 6mm, the sealing performance and the wear resistance are good, and the service life is long.

In some embodiments of the present disclosure, the on-line viscometer 11 can be selected from VA-300M manufactured by MARIMEX, Germany, which is the on-line viscometer most suitable for on-site control at present by using the principle of torque motion. Displaying the viscosity and the temperature in real time, having pressure and temperature compensation, and the viscosity range is 1-25000mPa & s; a temperature sensor ST300 is arranged in the temperature sensor, and the measuring range is-40 ℃ to 300 ℃; the precision is plus or minus 1% or 1 bit reading; the viscometer probe was made of 316L stainless steel.

In some embodiments of the present description, the online particle sizer 12 may be SOPAT-VI. The diameter of the probe is 6mm, the length of the probe is 120mm, the measuring range is 1-2000 mu m, the measuring pressure is 0-300bar, and the measuring temperature is-50-450 ℃. The proportion of different forms of particles occupied can be measured.

With continued reference to fig. 3a and 3b, in some embodiments of the present description, five sets of test cells are provided on the tank, with one linear viscometer 11 and one online particle sizer 3 provided in each test cell. In addition, at corresponding positions of each test unit, corresponding sampling ports 14 are respectively provided.

With continued reference to FIGS. 3a and 3b, in some embodiments of the present description, oil enters through the oil inlet lineAnd putting into a tank body. On the oil inlet pipeline, a centrifugal pump 4, a turbine flowmeter 5 and a hydraulic control valve 6 are sequentially arranged along the flow direction of oil products. In some embodiments of the present disclosure, the centrifugal pump 4 may be an SFB small stainless steel centrifugal pump, model 25SFB-8D, inlet diameter 25mm, outlet diameter 20mm, head in the range of 3-11m, flow rate in the range of 0.8-7.5m³In the range of/h. In some embodiments of the present disclosure, LWGY-20 turbine flowmeter, nominal diameter of 20mm, and standard range of 0.8-8m may be used as turbine flowmeter 5³H, wide range of 0.4-8m³And h, the precision grade is 0.5 grade. The device has the advantages of high precision, good repeatability, simple structure, high pressure resistance, wide measurement range, small volume, light weight, small pressure loss, long service life, simple operation, convenient maintenance and the like. The opening of the valve can be automatically controlled by selecting a hydraulic control valve according to the signal of the adjusting part, thereby achieving the adjustment of the medium flow.

In some embodiments of the present description, the stirring device (nozzle 7) may be of the type of a tank wall fixed nozzle, a tank center fixed nozzle, and a rotating nozzle, and may be replaced by being removed and installed at a flange position. The fixed nozzle (as shown in figure 5 a) on the tank wall is directly connected with the oil product inlet, and the injection angle is fixed; a plurality of spray heads can be arranged at the center of the tank and fixed with a fixed spray nozzle (as shown in figure 5b), and the spray angle is upward; the rotating nozzles (as shown in fig. 5c) can realize 360-degree rotating spraying of the nozzles through a pump arranged outside the storage tank, two spray heads are generally arranged on each nozzle, and the spray heads can automatically rotate and keep swinging within a 30-degree range due to reverse acting force between the spray heads.

In some embodiments of the present description, the stationary nozzle and the rotary nozzle may be provided at the center of the tank by providing a bracket. With particular reference to fig. 4, in this manner, the flange is formed, in particular, by the bracket 15, the external flange a-16 of the tank, the internal flange B-17 of the tank; and a can internal flange C-18.

With continued reference to fig. 3a and 3b, in some embodiments of the present description, the tank body may be integrally disposed on the base 13 to facilitate securing and oil discharge from the oil discharge port.

In addition, in some embodiments of the present disclosure, in the step of studying the wax dissolution of the oil sample, a large vortex simulation method may be used to calculate the flow field distribution of the sediment in the storage tank during the stirring process. Compared with a Reynolds time average method, the method can more accurately describe the unsteady vortex structure and the transient change process of the flow field.

The embodiments described in the present specification have at least one of the following advantages:

(1) the device for testing the relative hardness of the sediment layers with different heights in the crude oil storage tank can be used for carrying out non-contact real-time measurement on the hardness of the sediment layer at the bottom of the actual crude oil storage tank on site, which is realized by comparing the propagation speeds of ultrasonic waves in the sediment with different hardness with samples.

(2) Previous researches only can measure the total thickness of a deposit layer of a crude oil storage tank, and the device provided by the embodiment of the specification not only can measure the thickness of the deposit layer, but also can measure the hardness of the deposit layers with different heights.

(3) The ultrasonic generator is arranged on the wall of the tank but not on the top of the tank, and the ultrasonic generator arranged on the top of the tank reflects on a gas-liquid or gas-solid interface and can only measure the liquid level of the vault tank or the thickness of a settled layer of the inner floating roof tank and the outer floating roof tank. However, the ultrasonic generator of the invention is arranged on the wall of the tank and emits sound waves along the horizontal direction, so that the thickness and the hardness of the deposited layer can be measured.

(4) The device for testing the relative hardness of the sediment layers at different heights in the crude oil storage tank has continuity and accuracy of measured data. The ultrasonic transmitter is loaded on the carrying equipment to run along the slide rail of the tank wall, ultrasonic waves are transmitted and received in real time in the running process, data are transmitted and processed in real time, the measured data have continuity and accuracy, the automation degree is high, and convenience and rapidness are realized.

(5) In the method for reasonably predicting the start-stop time of the stirrer in the crude oil storage tank and adjusting the operation parameters, the physical properties of crude oil at different layers can be obtained, and the wax dissolving effect of oil samples of sediments with different hardness in the stirring process can be researched. The previous research usually only focuses on the flow field distribution during stirring, so that the scheme of the specification supplements and perfects the research on the stirring effect of the deposited layer by the stirrer, thereby more reasonably predicting the start-stop time of the stirrer and adjusting the operation parameters.

Examples of the invention

The following experimental examples may provide reference for those having ordinary skill in the art to practice the present invention or verify the effects. These examples do not limit the scope of the claims.

Experimental example 1

The present experimental example provides the steps of testing the relative hardness of the sediment layers at different heights in the crude oil storage tank using the apparatus shown in fig. 1a to 1c and fig. 2:

step 1: the transit time of the ultrasonic waves within the single-layer tank wall of the first vessel was measured. Cleaning a first container, then installing a movable testing component outside the first container, and measuring the transmission time of ultrasonic waves in the single-layer tank wall of the container, and recording the transmission time as t_{Container with a lid}。

Step 2: and configuring a deposited layer hardness sample. (1) Taking out the sediment from the bottommost part of the crude oil storage tank to be tested, placing the sediment in a first container, horizontally transmitting ultrasonic waves from the outer side of the tank wall of the container along the direction of the circle center by adopting a mobile testing assembly, returning along the original route when the sound waves reach the interface between the tank wall on the other side and air, calculating the propagation speed of the ultrasonic waves in the sediment under the hardness, and marking the propagation speed as v₁₀₀，v₁₀₀＝0.2/(t_{General assembly}-4t_Container) Corresponding to a hardness of 100%. (2) Taking out an oil sample from the top end of the crude oil storage tank to be tested, and mixing the oil sample with the sediment according to V_{Deposit material}:V_OilA deposit with a lower hardness was placed at a ratio of 9:1, and the propagation velocity of the ultrasonic wave in the deposit was measured by the same method as described above and was designated as v₉₀Corresponding to a hardness of 90%. (3) According to the steps, sediment samples with different hardness are sequentially prepared to obtain v₀、v₁₀、v₂₀……v₁₀₀There are 11 propagation velocities corresponding to 0%, 10%, 20%, … … 100% and 100% of 11 deposit hardnesses, respectively.

And step 3: and measuring the hardness of the sediment of the crude oil storage tank to be measured. (1) Install on the crude oil storage tank that awaits measuring and remove test assembly, specifically do: fixing a slide rail on the tank wall of the crude oil storage tank to be detected, wherein the bottom end of the slide rail is vertical to the ground; assembling a carrying trolley on a slide rail, and installing an ultrasonic probe, wherein the initial position of the trolley is the bottommost end of the storage tank; the detection module (which can be independently arranged) is used for detecting the distance between the ultrasonic probe and the tank wall, and the pressing device is adjusted to enable the ultrasonic probe to be tightly attached to the tank wall. (2) If the information of the control center shows that the ultrasonic probe is installed completely, the second control module (the PLC module 2) controls the ultrasonic probe to transmit signals, the sound wave signals reach the tank wall on the other side of the storage tank and return along the original route after reaching the air interface, are received by the ultrasonic probe again, and transmit the received information to the control center. (3) The carrying trolley is controlled through the first control module (PLC module 1), so that the carrying trolley is loaded with the ultrasonic probe and runs along the slide rail, the ultrasonic probe emits signals in the running process, and the received ultrasonic signals are transmitted to the control center in real time. (4) The control center processes the received ultrasonic signals, calculates the propagation speed of the ultrasonic waves in the sediments at each height, and compares the propagation speed with the sediment layer hardness sample to obtain the hardness of the sediments at each height of the actual storage tank.

Experimental example 2

The crude oil sedimentation layering experimental device is used for monitoring the wax dissolving effect of a sedimentary layer at the bottom of the stirring tank in real time in the sedimentary layer process, and the physical properties of crude oil at different layers can be obtained in real time. In the experimental example, the wax dissolving conditions of different oil samples are researched, the stirring effect of the rotary spray nozzle at the center of the tank on the settled layer is simulated, the tested oil samples are 1#, 2#, 3#, and 4# oil samples, and the properties of the oil samples are shown in tables 1 and 2.

TABLE 1 blank oil physical Properties test results

TABLE 2 blank oil 30 ℃ viscosity test results

The specific experimental steps are as follows:

step 1, crude oil pretreatment:

putting a batch of sealed glass bottles containing oil samples into a water bath, standing and heating to 80 ℃, keeping the temperature for 2 hours to enable the crude oil in the bottles to reach a uniform state by virtue of the thermal motion of molecules, standing and naturally cooling to room temperature, and storing the bottles in a place with small environmental temperature fluctuation for more than 48 hours, so that the oil samples are considered to be the base oil samples with the same constitution state.

Step 2, preheating an oil sample:

and opening the program-controlled water bath, heating the oil storage tank to the temperature of 30 ℃ for the experiment, and keeping the temperature for 10min when the control panel of the program-controlled water bath indicates that the temperature reaches 30 ℃. And (3) conveying the preheated experimental oil into the oil storage tank from the oil inlet through the pump, and stopping feeding the oil until the liquid level reaches the height 1/2 of the storage tank. Keeping the temperature for 30min to make the oil sample in the glass bottle reach a uniform state through the thermal movement of molecules.

Step 3, adding a tank bottom sediment:

and opening the top cover of the oil storage tank, uniformly containing the prepared sediments at the bottom of the oil storage tank, and covering the top cover.

Step 4, stirring the sediment:

the centrifugal pump of the oil inlet pipeline is started, the rotating nozzle at the center of the tank conveys oil through the oil pump to drive the turbine to rotate, the transmission device is utilized to drive the machine body to rotate, and the oil is sprayed into the tank at a high speed through the nozzle to form a spraying flow. The oil inlet speed is controlled by the adjusting valve, and the reading displayed by the turbine flowmeter is observed in real time, so that the stirring rotating speed is controlled at 800 r/min.

Step 5, viscosity temperature measurement:

the viscosity of oil products at different layers is measured by an on-line viscometer and recorded.

Step 6, separating and loading samples:

after the stirring time, the slurry was filtered through gauze, the amount of undissolved bottoms sediment was weighed, and the filtered liquid oil sample was quickly loaded into the measuring cylinder of the Anton Paar rheometer (oil sample loaded to the height of the marked scale line of the measuring cylinder).

Step 7, condensation point testing:

and (3) filling the residual filtrate into a preheated condensation point test tube, and testing the condensation point of the preheated condensation point test tube to ensure the consistency of the condensation point of each sample filled into the rheometer.

Step 8, determining wax precipitation point and wax content:

and (3) putting the prepared pattern into an aluminum dry pot, putting the aluminum dry pot into a DSC instrument, and measuring a wax precipitation point and a wax content.

The results for tank bottoms dissolved for blank crude oils of different properties are shown in table 3 below; the physical property test results of blank crude oils with different properties after dissolving tank bottom sediments are shown in the following table 4; the results of the viscosity measurements for the blank crudes of different properties after dissolution of the bottom sediment are shown in table 5 below.

TABLE 3 solubility test results of white oils of different properties for bottom sediments

TABLE 4 physical Properties test results after dissolving tank bottoms in blank crude oils of different natures

TABLE 5 viscosity test results of different properties of blank crude oils dissolved in bottom sediments of tanks

FIG. 6 is a curve showing the dissolution rate of blank crude oils with different properties to bottom sediments along with the change of wax content, and FIG. 7 is a curve showing the dissolution rate of blank crude oils with different properties to bottom sediments along with the change of viscosity. As can be seen from fig. 5a to 5c and fig. 6, under the condition that the treatment temperature, the stirring speed, the stirring time and the hardness of the bottom sediment are constant, the lower the wax content and the lower the viscosity of the blank crude oil, the better the solubility of the crude oil in the bottom sediment.

FIGS. 8-11 are plots of viscosity as a function of shear rate for 1#, 2#, 3# and 4# oil blank crudes, respectively, after incorporation into the bottoms. From fig. 8-11, it can be seen that the difference between the viscosity of the slurry formed after the different blank crudes are mixed into the bottom sediment and the viscosity of the crudes decreases with the deterioration of the oil properties, mainly because the worse the oil properties, the less the bottom sediment of the tank is dissolved by the crudes, and thus the less the physical property changes.

Experimental example 3

This experimental example provides the experiment that utilizes big vortex simulation to calculate the flow field distribution in the storage tank when stirring the sedimentary deposit, and the operating procedure is as follows:

step 1: a fixed nozzle model at the center of the tank shown in the figure 5b is established by adopting Solid Works three-dimensional modeling software, a flow field calculation domain is a cylindrical region formed by the diameter D of the storage tank and the height H of the liquid level, and the nozzle is positioned at the center of the bottom of the storage tank. The model is exported in parasolid format.

Step 2: and (3) introducing the three-dimensional model into ANSYS ICEM CFD software to carry out structured grid subdivision, dividing O-block outside the nozzle, and deleting block inside the nozzle. And outputting the Pre-Mesh convert to unstructured Mesh, and setting a solver as FLUENT.

And step 3: and (3) calculating the flow field distribution in the storage tank in the stirring process by adopting a FLUENT software three-dimensional double-precision pressure-based separation solver. A turbulence model: an LES model, wherein a sub-grid model selects Smagorinsky-Lilly and selects Dynamic Stress; fluid medium: setting according to the density and viscosity of the deposited layer; boundary conditions: the nozzle outlet is set as a speed inlet boundary condition, and the others are non-slip wall boundary conditions; pressure-velocity coupling: a PISO algorithm; spatial discrete format: the gradient term dispersion is Least Squares Cell Based, the pressure dispersion is Standard, and the momentum equation dispersion is bound Central Differencening; transient term solving: bounded Second Order im plicit format. And setting reasonable convergence residual errors according to different fluid speeds at the outlet of the nozzle, adjusting relaxation factors of pressure, density and momentum, and selecting a proper iteration step length.

And 4, step 4: and processing the calculation result by adopting Tecplot 360 visual post-processing software, and analyzing the flow field distribution at different moments in the stirring process by observing speed cloud charts, pressure cloud charts, flow charts, vorticity charts and the like of different sections.

It should be noted that, in the description of the present specification, the terms "first", "second", and the like are used for descriptive purposes only and for distinguishing similar objects, and no order is present therebetween, and no indication or suggestion of relative importance is to be made. Further, in the description of the present specification, "a plurality" means two or more unless otherwise specified.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the applicant consider that such subject matter is not considered part of the disclosed subject matter of the specification.

Claims

1. A method of adjusting the operation of a blender in a crude oil storage tank, the method comprising:

measuring the relative hardness data of the sediment layers with different heights in the crude oil storage tank to be measured by adopting the following device;

the device for testing the relative hardness of the sedimentary deposit at different heights in the crude oil storage tank comprises:

a first vessel for filling a crude oil storage tank sediment sample;

a mobile testing assembly removably mountable to an exterior of the first container sidewall or an exterior of a crude oil storage tank sidewall to be tested, the mobile testing assembly comprising: a guide rail; a carriage moving along the rail; the ultrasonic probe is arranged on the carrying equipment; a first controller for controlling movement of the vehicle; and a second controller for controlling the operation of the ultrasonic probe;

when the mobile testing component is detachably arranged outside the side wall of the first container, the ultrasonic probe is close to the outer wall of the first container to transmit ultrasonic signals and receive corresponding reflected signals;

when the mobile testing component is detachably arranged outside the side wall of the crude oil storage tank to be tested, the carrying equipment is close to the side wall of the crude oil storage tank and vertically moves along the guide rail, and the ultrasonic probe transmits an ultrasonic signal to the crude oil storage tank and receives a corresponding reflected signal;

the mobile testing assembly further comprises a pressing piece, and the pressing piece is used for enabling the ultrasonic probe to adjust or maintain a close state with the outer wall of the first container and/or the side wall of the crude oil storage tank;

the guide rail comprises two parallel slide rails; the carrying equipment is arranged between the two slide rails in a spanning mode, and a through hole used for accommodating the ultrasonic probe is formed in the carrying equipment body;

the pressing piece is arranged above the through hole;

the ultrasonic probe is accommodated in the through hole, and the distance between the ultrasonic probe and the side wall of the first container and/or the side wall of the crude oil storage tank can be adjusted through the pressing piece;

the material of the side wall of the first container is the same as that of the side wall of the crude oil storage tank;

dividing a sedimentary layer of the crude oil storage tank to be detected into a plurality of height intervals, and taking the average value of relative hardness data in the height intervals as the hardness of each height interval;

preparing a first experimental sample in a crude oil sedimentation layering experimental device; the first experimental sample comprises a sedimentary deposit simulation sample and an oil product simulation sample; the sedimentary deposit simulated sample comprises at least one sedimentary sublayer, and the hardness of the sedimentary sublayer is close to the hardness of a certain height interval of a sedimentary deposit in the crude oil storage tank to be detected; the oil product simulation sample is an oil product taken from a crude oil storage tank to be detected or an oil sample prepared by referring to the oil product; the crude oil sedimentation layering experimental device is a device for researching the dissolution condition of the sedimentary stratum simulation sample in the oil product simulation sample under the stirring condition; obtaining dissolution data of the sedimentary stratum simulation sample in the oil product simulation sample corresponding to different stirring conditions through the crude oil sedimentation and stratification experimental device;

2. The method of claim 1, wherein the sediment sub-layer is a sediment sample representing different hardness prepared for a bottom sediment and an oil product in the crude oil storage tank to be tested.

3. The method of claim 1, wherein the sediment layer simulation comprises at least two sediment sublayers for simulating two adjacent height intervals in the sediment layer of the crude oil storage tank to be tested.

4. The method of claim 1, wherein the dissolution data comprises physical property data or wax dissolution data of the oil simulant.

5. The method of claim 4, wherein the property data comprises density, congealing point, or viscosity.

6. The method of claim 1, further comprising:

calculating flow field distribution data of the deposition layer simulation sample in the container in the stirring process by a large vortex simulation method according to the dissolution data;

and further combining the flow field distribution data to adjust the start-stop time and/or the operation parameters of the stirrer in the crude oil storage tank.

7. The method of claim 1, wherein the step of obtaining relative hardness data for different height deposition layers comprises:

loading each sediment sample into the first container, and then acquiring the transmission speed of ultrasonic waves in each sediment sample by using the mobile testing component, wherein the transmission speed is recorded as a first speed, and the transmission speed are combined to form a first speed set;

acquiring the transmission speeds of ultrasonic waves in the settled layers of the crude oil storage tank to be tested at different heights by using the mobile testing component, wherein the transmission speeds are recorded as second speeds, and the second speeds are integrated to form a second speed set;

8. The method of claim 2, wherein the crude oil settling stratification test device comprises:

a tank for storing oil;

an oil inlet pipeline arranged on the tank body;

the stirring device is arranged in the tank body;

and the oil drainage port is arranged at the bottom of the tank body.

9. The method according to claim 8, wherein the stirring device comprises at least one stationary nozzle and/or a rotating nozzle.

10. The method of claim 9, wherein when the stirring device comprises a stationary nozzle, the stationary nozzle is disposed on the inner wall of the tank and the center of the tank; when the stirring device comprises a rotating nozzle, the rotating nozzle is arranged in the center of the tank body.