RU83338U1 - DEVICE FOR DETECTING OIL LEAKS AND PRODUCTS OF ITS PROCESSING - Google Patents

Abstract

A device for detecting leaks of oil and products of its processing, containing a tank and leak sensors, characterized in that the leak sensors are made in the form of plates and are located under the tank, while the bottom of the tank acts as one of the capacitor plates, and one of the plates located under the tank , plays the role of the second plate of the capacitor, the sand-gravel mixture plays the role of a dielectric, by changing the dielectric constant in which the fact and place of the leakage of oil and its products from p reservoir of.

Description

The utility model relates to the field of environmental protection from pollution by oil and other liquid hydrocarbons and can be used to detect leaks into the soil of oil and its products during their storage and transportation, as well as to detect not only the fact, but also the place of leakage from the tank oil and its refined products.

The well-known "Leakage sensor of oil products" [Patent No. 2190844 of 10.10.2002], which consists in the fact that to detect oil that has got into the soil, a sensor is used, which is two or more electrodes, one of which is surrounded by a dielectric layer, which is completely or partially made of material soluble in liquid petroleum products. Therefore, if there is a leak of oil products near the sensor located, the dielectric dissolves, the resistance between the electrodes of the latter decreases, which is recorded by a resistance meter (ohmmeter).

The main disadvantage of the known device is the complexity of the design of the sensor and the low accuracy of detection and registration of leakage of petroleum products by measuring the distributed resistance between the electrodes. In addition, it is impossible to accurately determine the place of leakage of oil products due to the measurement of the average resistance between the electrodes, because determination of the place of leakage of oil products is a multiple of at least the distance between the electrodes.

The objective of the claimed utility model is to create a device that allows you to detect a leak of oil and its refined products, which would accurately determine the fact and location of the leak,

providing reliability, safety of the device and ease of operation.

The specified technical result is achieved in that the device for detecting leaks of oil and products of its processing contains a tank 1 with a bottom 2 filled with oil or products of its processing. Between the bottom 2 of the tank 1 and the soil at a depth of H, plates 3 are placed at a distance L from each other, which in this case act as sensors for oil leakage and products of its processing, they are covered with a sand-gravel mixture (ASG) 4 or with Prekan, which obtained as a result of reagent neutralization of oil transportation waste. The sand-gravel mixture performs the function of the dielectric of an electric capacitor formed by the bottom of the tank and the plates located under it. The capacitance of the indicated electric capacitor changes according to the change in the permittivity of the CBC, the change in which determines the fact and place of the leakage of oil and its refined products from the tank. The number of metal plates (3) (П ₁ П ₂ , ... П _N ) corresponds to the number of sheets for cutting the bottom (2) of the tank (1), since if the integrity of the bottom (2) is violated on one of the plates, it will be replaced during repair this plate as a whole. According to the current regulatory documentation, local repair of less than the size of the sheet for cutting the bottom of the tank is unacceptable. In addition, a device for detecting oil leaks and its refined products contains an electronic switchboard EC (5), connecting each of the metal plates (3) with a KG crystal oscillator (6) connected to a personal computer (7).

Figure 1 presents a circuit for detecting leaks and schematically shows a device for detecting leaks of oil and its refined products.

Figure 2 shows a diagram of the connection of capacities to a quartz resonator.

The operation of the device for detecting leaks of oil and its refined products.

For storage of oil and products of its processing metal vertical steel tanks (RVS) are used. During construction, the bottom of the RVS is made of metal plates. The metal bottom of the tank acts as one of the plates of the condenser.

In general, an electric capacitor consists of 2 metal plates located parallel to each other, between which there is a dielectric. The electric capacitance C of the capacitor is determined by the formula:

where: C - capacitor capacitance (f);

ε is the dielectric constant of the dielectric (f / m);

S is the area of the plates (m ² );

D is the distance between the plates (m).

ε - permittivity - determines the ability of the dielectric to polarize in an electric field, is a quantitative estimate and is always> 1. [Handbook of elements of electronic devices, ed. N.A. Kulikovsky. M. "Energy" 1978, p.279]

Between the bottom of the PBC (2) and the soil at a depth of H and at a distance L from each other, metal plates 3 are placed, which act as the second capacitor plate. As a dielectric, the Prekan preparation or sand-gravel mixture (ASG) 4 can be used, which is always poured into the foundation under the bottom of the RVS. According to [Zhuravleva L.V. Electrical Materials M. IRPO, ed. Academy, 2002, p. 210] for glass, glass, silicon, (of which ASG consists) the value

dielectric constant ε lies in the range from 5 ... 7, for mineral oil, oil ε = 2,1 ... 2,3 [Zhuravleva L.V. Electrical Materials M. IRPO, ed. Academy, 2002, p.229].

If, as a result of corrosion or a crack in the bottom of the (2) PBC, oil or oil products leak through damage in the bottom, the ASG (4) is impregnated with this product and the dielectric constant of the latter decreases from 5 ... 7 to 2.1 ... 2.3 , and, as a result, the electric capacitance of the capacitor located in the leakage zone decreases, see formula (1). A decrease in capacitance is recorded by a change in the frequency of the KG (6) to which the plates (3) of the capacitors are connected alternately through an electronic switch (5) connecting each metal plate (3) in series with a crystal oscillator (6) connected to the PC (7).

Due to this, in the presence of leaks of oil or products of its processing near the location of one of the plates, the product is impregnated with ASG, which will entail a change in the dielectric constant of the material acting as a dielectric located between the bottom of the tank (2) acting as one capacitor plate and one of the plates (3) performing the function of the second capacitor plate. As a result of this, the electric capacitance of the capacitor formed between the bottom of the tank (2) and one of the plates (3) changes, which makes it possible to achieve reliable and reliable recording of not only the fact, but also the place of leakage of oil and its products from the tank into the ground.

Each metal plate (3) through an electronic switch (5) is connected in series to a crystal oscillator (6), which in turn is connected to a PC (7). The change in capacitance is recorded by changing the output frequency of the KG (6), the latter being connected in series with the quartz resonator (KR) (Figure 2) through the EC (5), which allows you to get the maximum conversion slope and

as a result, the maximum change in the frequency of the CT (6) from a change in the electric capacitance of the capacitor.

Thus, the output frequencies of the KG (6) (f _1: f ₂ , ... f _N ) depend on the value of the electric capacitances (C ₁ , C ₂ , ... C _N ) whose values, in turn, depend on the values of the dielectric the permeability of the ASG dielectric between the plates (3) and the bottom of the PBC (2).

Thus: the output frequency of the KG is a function of the capacitance

C ₁ , C ₂ , ... C _N : I; f _1; f ₂ , ... f _N = F (Ci, С ₂ ... С _N ),

which depends on the dielectric constant of the ASG located between the plates:

C ₁ , C ₂ , ... C _N = F (ε ₁ , ε ₂ ... ε _N ).

After assembling the structure, carrying out hydraulic tests of the reservoir, before starting the operation of the RCS, a control measurement of the capacitances C ₁ , C ₂ , ... C _{N is} carried out from each of the plates located in the ASG. Each value of the electric capacitance C ₁ , C ₂ , ... C _N corresponds to a certain value of the output frequency of the KG 6 f _1: f ₂ , ... f _N and a certain value of the dielectric constant of the ASG located between the plates (3) and the bottom of the tank (2 )

Control values of the output frequencies f _1; f ₂ , ... f _N are recorded in the registrar (8) and stored in the memory (10) and the database (9) (Figure 1) for storage and further comparison with frequencies f _1; f ₂ , ... f _NE obtained by measuring the capacitances C ₁ , C ₂ , ... C _{N of} each of the plates (3) during operation of the tank.

If there is a leak of oil or its refined products near the plates (3), the ASG is impregnated with this product, which leads to a change in the dielectric constant ε ₁ , and / or ε ₂ , and / or ε _N , and therefore to a change in the values of capacitances C ₁ , C ₂ , ... С _N and, as a consequence, a change in the output frequency of the CG (6).

During operation of the RVS, the operator, using EC (5) with a certain frequency, connects the plates (3) in series

P ₁ ; P _2; ... P _N to KG (6) and registers the obtained frequency values f _1E; f _2E , ... f _NE which then go to the PC (7) to compare these values with the control values of the frequencies of the CG (6) located in the database 9 of the PC (7).

Using the frequencies of KG 6 basic and received during operation, it is possible to assess the presence or absence of leakage of oil or its refined products from the RCS.

If the values of the output frequencies KG (6) of the control measurement are equal to the values of the frequencies during operation as a result of the running control f ₁ = f _1E , f ₂ = f _2E , ..., f _N = f _NE - there is no leakage. If the values of the frequencies of the control measurement and the frequencies of the round-trip control are not equal to f ₁ #f _1Э , f ₂ #f _2Э , f _N #f _NE , then we conclude that there is a leak, and the place of leakage is determined by the plate number and its location under the bottom PBC.

During operation and repair of RVS, it will be known not only about the fact of leakage of oil and its refined products, but will also help to identify the place of leakage, minimize the costs of repair and timely decommissioning of RVS in case of leakage and reduce the risk of environmental impact on the environment.

Device for detecting leaks works as follows. During the construction of the RVS, metal plates (3) are installed in the base of the tank (1) at a distance N from the bottom (2), which are connected to the crystal oscillator (7) through an electronic switch (6). The bottom (2) of the tank (1) is grounded by means of electrochemical protection (ECP). Under the base of the tank (1) between the bottom (2) and the plates (3), the drug Prekan or a sand-gravel mixture (4), which is a dielectric, is poured. Through the electronic switch (5), the plates (3) are connected in series to the crystal oscillator (6). If there is a leak near the location of a specific plate (3) (P ₁ , P ₂ , ... P _N ), the sand-gravel mixture (4) is impregnated with the leak product, the permittivity of the ASG changes, which leads to a change in capacitance C. Electronic switch (5)

sequentially connects the capacitor plates to the quartz generator (6) and the place of oil products leakage from the reservoir (1) into the ground is determined, since each plate P ₁ , P ₂ , ... P _N corresponds to a certain capacity C ₁ , C ₂ .. .C _N with a nominal frequency value f ₁ , f ₂ , ... f _N at the output of the crystal oscillator (6), as a result of which the frequency signal (KG) (6) is fed to the input of the PC port (7), is recorded and compared with initial frequency, which corresponded to the initial value of the tank without leakage of oil, which allows about Roedel fact and the leak of oil and refined products.

The proposed device allows you to detect a leak of oil and its refined products and quickly and accurately determine the fact and location of the leak, thereby ensuring safety and reliability during operation of the tank and during repair and restoration work.

Claims (1)

A device for detecting leaks of oil and products of its processing, containing a tank and leak sensors, characterized in that the leak sensors are made in the form of plates and are located under the tank, while the bottom of the tank acts as one of the capacitor plates, and one of the plates located under the tank , plays the role of the second plate of the capacitor, the sand-gravel mixture plays the role of a dielectric, by changing the dielectric constant in which the fact and place of the leakage of oil and its products from p reservoir of.