An experimental device for studying the boilover spatter characteristics of an oil tank

Abstract

An experimental device for studying the boiling overflow spatter characteristics of an oil tank, mainly characterized by comprising an oil tank, a spatter monitoring dome, a heating module, a cross-section imaging module, and a high-speed camera. The process of heat transfer from the flame to the liquid surface during actual combustion is simulated by using grid heating, thereby inducing the occurrence of boiling overflow spatter. The oil-steam distribution evolution law of the storage tank can be recorded in real time by using a capacitance-conductance combined probe combined with a high-speed camera, and the trajectory of the spattered oil droplets can be measured. Compared with traditional boiling overflow spatter devices, the present application has the advantages of ingenious design, high safety, multiple measurement parameters, and wide application in the study of oil boiling overflow spatter rules.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas storage and transportation safety, and relates to an experimental device for studying the boiling overflow spatter characteristics of a small-scale oil tank. BACKGROUND

[0002] In recent years, with the development of the national economy and the implementation of the oil reserve plan, oil tanks are widely used as the main way of oil storage. However, once a fire breaks out in an oil tank, it will cause huge economic losses and casualties if not controlled in time. Therefore, the research on oil tank fires, especially the research on the boiling overflow spatter characteristics of oil tanks in oil tank fires, has become a research focus. At present, the research on the boiling overflow spatter characteristics of oil tanks mainly includes small-scale research and large-scale experimental research. The large-scale experimental research has the disadvantages of large scale, high experimental cost and high experimental risk, while the small-scale experimental research has the advantages of low experimental cost and easy measurement of experimental parameters. Therefore, for the research on the boiling overflow spatter characteristics of oil tanks, small-scale experimental research is the main research method.

[0003] At present, the simulation experiment for studying the boiling overflow spatter characteristics of a small-scale oil tank mostly uses a closed stainless steel container with a water cushion layer added below to simulate the combustion conditions when the oil tank is on fire. However, these combustion simulation devices have the following disadvantages:

[0004] (1) The experiment is conducted in a burning mode, which has a high safety risk, and the distribution of the spattered oil and water, i.e. the spatter trend, cannot be analyzed and sorted. Three conditions are needed for the boiling overflow spatter of an oil tank: the oil tank contains a certain proportion of water, the oil has the moving heat wave characteristic, and the oil has a certain viscosity. Boiling overflow or spatter is essentially caused by the phase change of water in crude oil due to heating. Therefore, according to the physical nature of boiling overflow spatter of an oil tank, non-combustion heat conduction can be used to induce boiling overflow;

[0005] (2) The traditional boiling overflow experiment cannot analyze and study the changes of the oil-water interface when boiling overflow occurs, and cannot analyze the distribution of gas and liquid in the tank when boiling overflow occurs. According to the boiling overflow mechanism, boiling overflow occurs due to the sudden expansion of the water layer caused by the phase change of the bottom water layer, which causes the oil layer above the water layer to be spattered out of the tank under the pressure of the lower water layer, resulting in the occurrence of boiling overflow. However, the existing experimental devices for studying the boiling overflow spatter characteristics of oil tanks mostly use a closed stainless steel container for experiments, which makes it difficult to observe the changes of the oil-water interface when boiling overflow occurs. In addition, few people pay attention to the distribution of water droplets and oil droplets spattered out of the tank after the oil boils over. SUMMARY

[0006] The present application aims at the defects of the prior art, and provides a tank boiling overflow and splashing experimental device, which can effectively simulate the whole process of tank boiling overflow and splashing, reduce the safety hazards in the experimental process, and can observe the distribution of gas-liquid phase in the tank when boiling overflow occurs, and record and analyze the distribution of gas-liquid phase in the tank when boiling overflow occurs. Compared with the prior art, the present application has the advantages of low measurement cost, multiple detection parameters, low experimental risk and the like.

[0007] An oil tank boiling overflow and splashing experimental device mainly comprises an oil tank, a splashing monitoring dome, a heating module, a cross-section imaging module and a high-speed camera.

[0008] The simulation oil tank is mainly composed of high-temperature-resistant transparent glass, and the change of the oil-water interface when boiling overflow and splashing occur can be observed.

[0009] The splashing monitoring dome is in a semispherical structure, is located directly above the simulation oil tank, is supported by a stand column below, the height of the stand column is about 1 times the height of the simulation oil tank, the diameter of the dome is 2-3 times the diameter of the simulation oil tank, and the dome is also supported by transparent glass and is provided with meridian and parallel lines distributed thereon for displaying the position of splashing oil drops.

[0010] The heating module mainly comprises a heating net, a support rod, a temperature control knob and a power line, the temperature control knob is used for controlling the temperature of the heating net, the heating net is arranged in the oil layer of the simulation oil tank and is used for heating the oil in the simulation oil tank, and the heating net simulates the heat transfer process of the flame to the liquid surface during actual combustion, so as to induce the occurrence of boiling overflow and splashing.

[0011] The cross-section imaging module is composed of a combined probe, a terminal, a concentrator and an imaging computer, the combined probe is composed of a capacitance probe and a conductance probe in parallel, a plurality of combined probes are arranged in a grid structure in longitudinal and transverse equal intervals, the conductance probe is made of a metal wire, the capacitance probe has a conductive metal core wire inside and an insulating layer outside, the cross sections of the capacitance probe and the conductance probe are both semicircular, the outer diameter of the capacitance probe is the same as that of the conductance probe, and the two form a circular cross section after being combined, one end of the combined probe is fixed to the outer wall of the simulation oil tank and is sealed by epoxy resin, the other end of the combined probe is connected with the terminal, one combined probe corresponds to one terminal, and the conductive metal core wire of the capacitance probe and the conductance probe in the combined probe are respectively connected with two terminal posts of the node terminal; the terminal posts are connected with the concentrator through wires, and the concentrator is connected with the imaging computer through a signal line.

[0012] The beneficial effects of the present invention are as follows: the present invention can provide a new and highly similar experimental device for simulating the boiling and splashing of oil tanks; reduce experimental safety hazards and costs; observe and record the changes in the oil-water interface during the entire experimental process; observe and analyze the distribution of gas and liquid phases in the boiling tank; and analyze and judge the splashing trend of the liquid splashing out of the tank, that is, the oil-water two-phase; the entire simulation device has small error, high flexibility and strong repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attachment Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Attachment Figure 2 This is a top view of the splash monitoring dome;

[0015] Attachment Figure 3 Schematic diagram of the heating module;

[0016] Attachment Figure 4 Schematic diagram of the cross-sectional imaging module;

[0017] Attachment Figure 5 Schematic diagram of the combined probe structure;

[0018] Attachment Figure 6 Schematic diagram of cross-sectional imaging.

[0019] In the above figure: 1. Simulated oil tank; 2. Splash monitoring dome; 3. Heating module; 4. Cross-sectional imaging module; 5. High-speed camera; 6. Heating grid; 7. Support rod; 8. Temperature control knob; 9. Power cord; 10. Combination probe; 11. Terminal block; 12. Hub; 13. Imaging computer; 14. Capacitance probe; 15. Conductivity probe; 16. Conductive metal core wire; 17. Insulation layer. DETAILED DESCRIPTION

[0020] Combine Figures 1-6 , describes the specific implementation methods of the present invention.

[0021] like Figure 1 As shown, an oil tank boiling and splashing experimental device disclosed in the present invention mainly includes a simulated oil tank 1, a splashing monitoring dome 2, a heating module 3, a cross-sectional imaging module 4 and a high-speed camera 5.

[0022] The simulated oil tank 1 is mainly composed of high-temperature resistant transparent glass, which can be used to observe the oil-water interface and the phase distribution evolution process of the oil-water interface when boiling and splashing occur.

[0023] like Figure 1As shown in the figure, the splash monitoring dome 2 is a hemispherical structure, which is located directly above the simulation tank 1 and is supported by columns below, the height of the columns is about 1 times the height of the simulation tank 1, the diameter of the dome is 2-3 times the diameter of the simulation tank 1, and the dome is also made of transparent glass.

[0024] As shown in the figure, Figure 2 The splash monitoring dome 2 is provided with a grid distribution for displaying the position of the splash oil droplets. The high-speed camera 5 arranged on the top can record the change of the splash oil trace over time.

[0025] As shown in the figure, Figure 3 The heating module 3 mainly consists of a heating net 6, a support rod 7, a temperature control knob 8 and a power line 9. The temperature control knob 8 is used to control the temperature of the heating net 6, and the heating net 6 is placed in the oil layer of the simulation tank 1 to heat the oil in the simulation tank 1. The function of the heating net 6 is to simulate the heat transfer of the flame to the liquid surface during actual combustion, thereby inducing the occurrence of boiling overflow and splash phenomenon.

[0026] As shown in the figure, Figure 4 The cross-section imaging module 4 consists of a combination probe 10, a terminal 11, a concentrator 12 and an imaging computer 13. The combination probe 10 is composed of a capacitance probe 14 and a conductance probe 15 in parallel, and a plurality of combination probes 10 are arranged in a grid structure with equal intervals. The conductance probe 15 is made of a metal wire, and the capacitance probe 14 has a conductive metal core 16 inside and an insulating layer 17 outside. One end of the combination probe 10 is fixed to the outer wall of the simulation tank 1 and sealed by epoxy resin, and the other end of the combination probe 10 is connected to the terminal 11. One combination probe 10 corresponds to one terminal 11, and the conductive metal core 16 of the capacitance probe 14 and the conductance probe 15 in the combination probe 10 are connected to the two terminal posts of the terminal 11 respectively. The terminal posts of the terminal 11 are connected to the concentrator 12 through wires, and the concentrator 12 is connected to the imaging computer 13 through signal lines.

[0027] As shown in the figure, Figure 5 The cross-sections of the capacitance probe 14 and the conductance probe 15 are both semicircular, and the outer diameter of the capacitance probe 14 is the same as that of the conductance probe 15. After the combination of the two, a circular cross-section is formed.

[0028] As shown in the figure, Figure 6As shown, the working principle of the cross-section imaging module 4 is shown. The capacitive probe 14 proposed by the present application is coated with an insulating layer 17, and the middle conductive metal core wire 16 and the surrounding fluid medium form a cylindrical capacitor, so that the size of the capacitance between the conductive metal core wire 16 and the electric conductive probe 15 is related to the length of the vapor bubble contacted by the capacitive probe 14. The distribution of the vapor bubble in the transverse direction can be determined by a series of transversely arranged combination probes 10; the distribution of the vapor bubble in the longitudinal direction can be determined by a series of longitudinally arranged combination probes 10. The combination of the two can determine the shape and position of the vapor bubble in the cross-section.

[0029] The working process of the present application is as follows:

[0030] A water layer is arranged at the bottom of the simulated oil tank 1, and experimental oil is filled above the water layer. The heating net 6 is placed in the oil layer of the simulated oil tank 1, and the temperature of the oil layer is gradually increased by heating the oil layer, so that the heat wave surface is formed and transferred to the water layer below. When the temperature of the liquid water rises to the boiling point, phase change will occur to generate a large number of bubbles, and boiling overflow phenomenon will occur. The high-speed upward bubbles even carry oil to spray outside the tank, causing splashing.

[0031] The simulated oil tank 1 is composed of high-temperature-resistant transparent glass, and the flowing image of the side of the storage tank when the boiling overflow and splashing occur can be shot from the outer wall of the tank by the high-speed camera 5. The oil-vapor distribution characteristics on the cross-section of the storage tank are measured by the cross-section imaging module 4. The combination probes 10 are arranged in a mesh structure, and the conductive metal core wire 16 and the electric conductive probe 15 of each combination probe 10 are respectively connected to the corresponding terminal 11. The measurement signals of the terminal 11 are collected on the hub 12, and finally input into the imaging computer 13. Through the built-in algorithm, the oil-vapor distribution on the cross-section of the storage tank is imaged in real time. Therefore, the cross-section imaging module 4 combined with the high-speed camera 5 can obtain the whole process of the evolution of the oil-vapor interface when the boiling overflow and splashing occur.

[0032] When the splashing occurs, the sprayed oil droplets will collide with the splashing monitoring dome 2, so that an oil trace is formed on the dome. The meridian and parallel lines arranged on the dome can determine the splashing position of each oil droplet. By recording the distribution change of the oil trace on the dome, the basic parameters such as the splashing angle can be analyzed, and scientific basis for reducing the harm of splashing is provided.

[0033] The present application can propose a new experimental device for studying the boiling overflow and splashing characteristics of the oil tank, observe and record the evolution law of the oil-vapor distribution of the storage tank, and measure the trajectory of the splashing oil droplets. Compared with the traditional boiling overflow and splashing device, the present application has the advantages of ingenious design, no open flame, high safety, and many measured parameters, and can be widely applied to the research on the boiling overflow and splashing law of oil products.

[0034] The embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the above-described specific embodiments, and other various equivalent modifications, replacements, or changes can be made to the present application according to the ordinary technical knowledge and means in the art without departing from the above-described basic technical idea of the present application, and all of them belong to the protection scope of the present application.

Claims

1. An experimental device for studying the boiling and splashing characteristics of oil tanks, characterized by: The invention comprises a simulated oil tank (1), a splash monitoring dome (2), a heating module (3), a cross-sectional imaging module (4) and a high-speed camera (5); the simulated oil tank (1) is made of high-temperature resistant transparent glass, which can be used to observe the changes in the oil-water interface when boiling and splashing occur; the splash monitoring dome (2) is a hemispherical structure, the dome is located directly above the simulated oil tank (1), and the bottom of the dome is supported by a column, the height of the column is 1 times the height of the simulated oil tank (1), the diameter of the dome is 2-3 times the diameter of the simulated oil tank (1), and the dome is 1-2 times the diameter of the simulated oil tank (1). The top is also made of transparent glass, on which latitude and longitude lines are arranged for displaying the location of the splashing oil droplets; the heating module (3) is composed of a heating net (6), a support rod (7), a temperature control knob (8) and a power cord (9); the temperature control knob (8) is used to control the heating temperature of the heating net (6); the heating net (6) is placed in the oil layer of the simulated oil tank (1) for heating the oil in the simulated oil tank (1), simulating the heat transfer of the flame to the liquid surface during real combustion, thereby inducing the occurrence of boiling and splashing; the cut-off The surface imaging module (4) is composed of a combination probe (10), a terminal (11), a hub (12), and an imaging computer (13). The combination probe (10) is composed of a capacitance probe (14) and a conductivity probe (15) in parallel. A plurality of combination probes (10) are arranged at equal intervals vertically and horizontally to form a mesh structure. The conductivity probe (15) is made of a metal wire. The capacitance probe (14) has a conductive metal core wire (16) inside and an insulating layer (17) on the outside. One end of the combination probe (10) is fixed on the analog The outer wall of the oil tank (1) is sealed with epoxy resin. The other end of the combination probe (10) is connected to the wiring terminal (11). One combination probe (10) corresponds to one wiring terminal (11). The conductive metal core wire (16) and the conductivity probe (15) of the capacitance probe (14) in the combination probe (10) are respectively connected to the two wiring posts of the wiring terminal (11). The wiring posts of the wiring terminal (11) are connected to the hub (12) through a wire, and the hub (12) is connected to the imaging computer (13) through a signal line.

2. The experimental device for studying the boiling and splashing characteristics of oil tanks according to claim 1 is characterized by: The cross sections of the capacitance probe (14) and the conductivity probe (15) are both semicircular. The outer diameter of the capacitance probe (14) is the same as that of the conductivity probe (15). The two are combined to form a circular cross section.

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