RU141279U1 - DIAGNOSTIC DEVICE FOR LEAKAGE OF THE BOTTOM OF THE GROUND VERTICAL RESERVOIR FOR OIL AND OIL PRODUCTS USING A TWO-CABLE - Google Patents

Abstract

A device for diagnosing leaks from the bottom of a ground-based vertical tank for oil and oil products using a two-wire cable, characterized in that under the bottom of the tank, a two-core cable is laid into the ground horizontally and spiralwise along the diameter of the tank with insulation insulated through a certain distance, which is connected to the ends through communication lines with terminals of the electronic switch, while an ohmmeter is connected to the electronic switch, connected via a communication line with a computer, and also a resistance measurement periodically made between the ends of two-conductor cable, which allows to determine the presence and location of leaks of petroleum products from the tank bottom.

Description

The utility model relates to devices for storing oil and oil products. It can be used in the petrochemical and oil industries.

The proposed utility model is most applicable for storing oil and oil products of various grades at oil-gathering stations and oil depots under construction and reconstruction, equipped with large-capacity vertical surface steel tanks (RCS).

Pollution of the lithosphere and hydrosphere occurs as a result of fuel leaks from reservoirs and pipelines, PBC overflows with oil products, spills from hoses, tankers and other reasons.

1. If a spill of fuel from the tank’s belts can be detected visually, then the leakage of oil products from the bottom of the ground RCS can be determined only by complex diagnostic methods. These methods are associated with the release of the tank from the fuel with the subsequent cleaning of the RVS and are carried out with a certain frequency on average 1 time in 5-8 years, depending on the life of the tank [V.N. Zaichenko. New technologies for the repair of steel tanks. M .: OJSC TsNIITneftekhim, 2002.].

During operation, the bottom of the RVS is exposed to various types of corrosion, which are associated with the presence of sulfur and other aggressive compounds in oil and oil products, as well as water in the tank and in the ground.

Combating the loss of fuel from leaks through the bottom of the RCS is becoming an important environmental and economic challenge.

2. Known vertical cylindrical steel tank for light petroleum products [V.N. Zaichenko. New technologies for the repair of steel tanks. M .: OJSC TsNIITneftekhim, 2002.]. This tank has a bottom, a wall and a fixed roof. For receiving and dispensing petroleum products, reservoirs of this type have acceptance pipes. From the outside, valves are connected to them. In order to provide “small” and “large” tank breaths, there is a breathing valve. A metering hatch is installed on the roof of the tank, which serves to measure the level and take fuel samples.

Also on the tank there are monitoring and signaling devices (level gauges, samplers, level indicators, fire-fighting devices) and other equipment (manhole, light sunroof, safety valves).

The disadvantages of this tank when storing oil and oil products are:

1. The absence of a device to diagnose the detection of fuel leaks from the bottom of the tank.

2. High levels of air pollution by vapors of petroleum products and lithosphere by fuel leaks.

Also known is a portable device for operational monitoring and diagnostics of the bottoms of vertical steel tanks in operation [D.D. Kostrovsky. Operation of military rocket fuel and fuel depots. M .: Military Publishing, 1992.- 416 p.]. The operation of this device is reduced to sensing the soil under the bottom of the tank with an oil product to identify the location of leaks of oil products at the place of detection of electrical anomalies. Electrical anomalies are associated with increased and decreased resistivity relative to the background value of the soil under the bottom of the tank. The technical device for operational monitoring and diagnostics of the bottoms of vertical steel tanks includes metal probes from 8 to 16 pieces, a cross cable, a meter of electrical quantities (ohmmeter), and also electrical connectors.

The device operates as follows. At equal intervals, metal probes are introduced into the soil around the base of the tank. An electrical meter (ohmmeter) is connected to the metal probes using electrical connectors using a cross-cable. Using metal probes and a meter of electrical quantities, a soil probe is carried out under the bottom of the tank by measuring the resistance between adjacent pairs of probes in the sequence (1-2, 1-3, 1-4, 1-n, 2-3, 2-4,2-5 , 2-n, 3-4, etc.). The data of the measurement results are entered in the table. Then, using the coefficients, the actual results are recalculated into specific units, which are also entered in the table. After that, the abnormal values of the indicators are selected and the place of the leakage of oil products is graphically determined from them on the bottom sketch.

The disadvantages of this device when diagnosing the bottom of the vertical steel tanks are:

1. The absence of this device in stationary tanks of oil depots and fuel depots.

2. Low accuracy of determination in the winter period, as well as in conditions of high soil moisture.

3. The duration and complexity of the determination.

Also known is a ground-based vertical tank with a double bottom, equipped with a vapor recovery unit and a device for diagnosing the bottom [Yu.A. Matveev, S.G. Novikov, I.O. Zolotovsky. Utility Model Patent No. 114674 of April 10, 2012, “A vertical ground tank with a double bottom, equipped with an oil vapor recovery unit and a device for diagnosing the bottom”].

To a tank having a receiving and distributing branch pipe, a pipeline for receiving and dispensing oil and oil products, valves, light and metering hatches, a pressure relief valve, a manhole, a pressure breathing valve, an additional pipeline with a check valve and a valve connected to a recessed a reservoir with a low-octane component, the inner and outer bottom with stiffeners, in addition, a hydrophobic compound layer with a fiber optic distributed sensor is equipped on the inner bottom pressure monitor, which is connected by a communication line with an optical reflectometer and a personal computer. The tank is equipped with a portable sound source with a cable. In this case, the sound source is connected via communication lines to an amplifier and a personal computer.

The device operates as follows. The oil enters the reservoir through the intake pipe. In this case, the fuel level begins to increase, and accordingly the volume of the steam space decreases.

After filling the tank, the volumes of fuel and steam space are stabilized.

In order to diagnose the inside of the tank with a petroleum product with a certain frequency, which depends on the life of the tank, a sound source is lowered through a skylight with a cable, which is connected to the amplifier by communication lines and a personal computer.

The fiber-optic distributed pressure sensor is connected to an optical reflectometer and a personal computer, which can record mechanical changes along the length of the cable. Each cable section, depending on the mounting configuration, has its own section of the tank bottom.

Waves created in the tank by a sound source propagate in a liquid medium (fuel) and a solid medium (bottom). The intensity of the transmitted sound waves will depend on the thickness of the liquid and solid media. When the transmitted sound wave interacts with a fiber-optic distributed pressure sensor, the latter causes mechanical stresses distributed along the length. Assessing the intensity of stresses using recording equipment will make it possible to observe the distribution pattern of the thickness of the inner bottom and to evaluate the level of breakthrough hazard and potential fuel leakage by given parameters.

The disadvantages of the ground vertical tank with a double bottom, equipped with a vapor recovery unit and a device for diagnosing the bottom are:

1. Deposition on the bottom of water tanks, solids, resins, acids and other contaminants, which significantly reduces the accuracy of determination.

2. The high cost of equipment and instruments, as well as the duration, complexity and complexity of the determination.

3. The possibility of accumulation of explosive vapor-air mixtures between the bottoms, as well as increased metal consumption of the tanks.

Closest to the indicated problem is a ground vertical tank for oil and oil products, equipped with a stationary bottom diagnostic device [Yu.A. Matveev, S.G. Novikov, A.A. Butuzov, T.Yu. Martseva, A.V. Berintsev. Utility Model Patent No. 131014 of 08/10/2013, “A vertical ground tank for oil and oil products, equipped with a stationary bottom diagnostic device”].

Under the tank, with receiving and distributing nozzles, a pipeline for receiving and dispensing oil and oil products, valves, light and metering hatches, a ventilation hatch, an overpressure breathing valve, a manhole, an operating pressure breathing valve, a bottom additionally in the ground at a certain distance from the bottom of the tank horizontally equipped with metal probes of the first level, perpendicular to which are installed metal probes of the second level, while metal probes of different levels using lines ides are connected to electronic switches having terminals for connecting communication lines of specific metal probes. Electronic switches using a communication line are connected by a device for determining resistance by an ohmmeter, which is connected to a laptop computer.

In order to diagnose the bottom of the tank with a set frequency, which depends on the life of the tank using the communication lines of electronic switches and an ohmmeter, successive measurements of resistances between metal probes of various levels are carried out, which are displayed on a computer. At the same time, each measurement has its own section of the bottom of the tank.

High resistance values refer to the accumulation of petroleum products.

Evaluation of the resistance values between individual probes of different levels located perpendicular to each other using electronic switches, an ohmmeter and a computer allows us to determine not only the presence of a leak of oil products from the bottom of the tank, but also to identify a specific leak point in order to effectively repair the tank.

The disadvantages of a ground-based vertical tank for oil and oil products, equipped with a stationary bottom diagnostic device are:

1. A large number of metal probes, which increases the intensity and cost of the device.

2. The duration and complexity of the determination.

3. Insufficient determination accuracy with low leakage, since the oil product must soak the soil between the probes of different levels.

The solution to this problem is achieved by the fact that under the bottom of the tank horizontally and spiralwise along the diameter of the tank a two-core cable is laid in the ground with insulation stripped over a certain distance, which is connected at its ends via communication lines to the terminals of the electronic switch, while an ohmmeter connected to the electronic switch is connected through communication line with the computer, as well as the fact that periodically measurements of the resistance between the ends of the two-core cable, which allow to determine the presence and location of oil leaks from the bottom of the tank.

These signs are essential for solving the problem of the utility model, since the efficiency of determining fuel leaks from the bottom of the tank without releasing it increases, metal consumption and cost of the device decrease, the determination time is reduced, and the reliability of the tank farm operation increases.

The essence of the utility model is illustrated by drawings (Fig. 1, Fig. 2), which depict: a section of a tank, a top view of a two-wire spiral cable connected at its ends by communication lines with an electronic switch, an ohmmeter, and a computer.

Under the proposed reservoir 1 (Fig. 1), having a receiving and distributing branch pipe 2, a pipeline for receiving and dispensing oil and oil products 3, a valve 4, light and metering hatches 5.6, a ventilation hatch 7, an overpressure breathing valve 8, a hatch a manhole 9, a breathing valve of working pressure 10, the bottom 11, a twin-core cable 13 is laid horizontally and spiralwise along the diameter of the tank 1 in the soil 12, which connects its ends 14 through communication lines 15 to the terminals 16 of the electronic switch 17 and to the electronic switch An ohmmeter 18 is connected using the communication line 15, which is connected by a communication line 15 to the computer 19. The twin-core cable at certain distances has sections with stripped insulation 20, which are necessary to determine the exact place of oil product leakage from the tank.

The utility model works as follows. Through the intake pipe 3, the oil 21 enters the tank 1.

In order to diagnose the bottom 11 of the tank 1 with a set frequency, which depends on the life of the tank using the communication lines 15 of the electronic switch 17 and an ohmmeter 18, alternate measurements of the resistance between the ends 14 of the two-core cable 13 with stripped insulation 20, which are output to the computer 19.

The computer has a calculation program that allows you to determine not only the leak of fuel from the bottom of the tank, but also the specific location of the leak.

The deviation of the values from the experimentally obtained during the initial measurement of soil resistance, indicates the presence of leakage from the tank. High resistance values refer to the accumulation of petroleum products.

Estimation of the resistance values between the ends of a two-core cable with stripped insulation laid horizontally and spiralwise along the diameter of the tank using an electronic switch, an ohmmeter and a computer allows us to determine not only the presence of a leak of oil products from the bottom of the tank, but also to identify a specific leak point in order to effectively repair the tank.

Claims (1)

A device for diagnosing leaks from the bottom of a ground-based vertical tank for oil and oil products using a two-wire cable, characterized in that under the bottom of the tank, a two-core cable is laid into the ground horizontally and spiralwise along the diameter of the tank with insulation insulated through a certain distance, which is connected to the ends through communication lines with terminals of the electronic switch, while an ohmmeter is connected to the electronic switch, connected via a communication line with a computer, and also a resistance measurement periodically made between the ends of two-conductor cable, which allows to determine the presence and location of leaks of petroleum products from the tank bottom.

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