RU2699749C1 - Vapour recovery system during oil products reception and storage at oil storage tanks - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: system for catching vapours when receiving and storing oil products at petroleum storage depots relates to devices for trapping oil vapours and can be used in oil industry. Invention includes separate tank for collection of vapours, main steam line with sections, refrigerating unit, compressor, relays, manometers, check valves with different opening pressure, buried reservoir, electric motor, shaft with centrifugal wheels. At the same time the buried reservoir has two sections and is partially filled in one section with low-octane component, and in the other - with gasoline A-76. Technical result is achieved by pumping of vapours by compressor, from "big" breaths into separate reservoir for collection of vapours with subsequent supply through check valve of high pressure of vapours into section of reservoir with low-octane component, which is equipped with shaft with centrifugal wheels and cooling element. At that, compressor, refrigerating unit, electric motor for shaft rotation and gate valve are switched off periodically by means of appropriate manometers and relays. Vapours from "small" breaths enter the second section of reservoir with gasoline A-76 and turn into liquid due to temperature reduction in underground reservoir.

EFFECT: mixture of light fractions of petroleum products with benzene A-76 can be used for addition of commercial grade gasoline normal-80 and A-76.

4 cl, 2 dwg

Description

The invention relates to a device for trapping vapors of petroleum products and can be used in the petrochemical and other industries of petroleum products.

The invention is most applicable when issuing and receiving automobile gasolines of various grades at oil depots. Air basin pollution at oil depots occurs when oil product vapors are released in the process of “large” and “small” tank breathing, fuel is dispensed into machine tanks, improper installation of breathing equipment, and other reasons. Losses from "big breaths" are due to the displacement of the vapor-air mixture (PVA) from the reservoir when receiving the oil product. In this case, the volume of gas space decreases and the breathing valve is activated. Losses from “small” breaths are caused by daily fluctuations in temperature and partial pressure of fuel vapor (mainly gasoline) in the gas space of the tank [V.G. Kovalenko Ecological safety in oil products supply systems and automobile transport. M .: LitNefteGaz, 2004].

The temperature of petroleum products stored in ground tanks depends on the ambient temperature. In the summer, oil products in ground vertical steel tanks (PBC) are heated to 30 degrees Celsius or more. The gas boiling point is 35 degrees Celsius [V.V. Anferov, V.G. Kovalenko, A.N. Rementsov. Technical equipment and personnel in oil products supply systems. Tutorial. M: MADI. 2006]. At this temperature, low-boiling gasoline fractions turn into steam and escape into the environment through a breathing valve.

Characteristic features in the operation of oil depots are the storage, reception and delivery of fuel to railway and automobile tanks. This means significant evaporation loss. This circumstance not only leads to fuel losses, but also negatively affects the health of the population. Combating the loss of petroleum products from “large” and “small” breathing tanks at oil depots is becoming an important environmental and economic challenge.

A known installation of vapor recovery of petroleum products from automobile tanks and tanks using a cooling mixture [Yu.A. Matveev et al. Utility Model Patent No. 122994 of December 20, 2012].

In this installation, a removable device is mounted on the neck of a car tank on a flexible sleeve, which is connected to a section of the steam pipeline of a loading and unloading trestle. A compressor for pumping oil vapor and a non-return valve are installed on the steam pipeline section. The section of the steam pipeline of the loading and unloading trestle is connected to the main steam pipeline with a non-return valve and a valve that connects to a recessed horizontal steel tank. The tank is equipped with an activated carbon filter-absorber and a device for receiving oil vapor and is half filled with a low-octane component, which is used as diesel fuel. The main steam line under the earth's surface is a coil-type heat exchanger with a cooling mixture representing a 15% aqueous solution of sodium carbonate. This cooling mixture is economically feasible, since it has a low cost and high efficiency, which allows to reduce the temperature in the heat exchanger to 7-9 degrees Celsius relative to the temperature of the earth's surface. The cooling mixture from the tank is fed to the heat exchanger through a cooling system pipe equipped with valves using a pump. The heat exchanger is equipped with elbows and a drain valve for draining the cooling mixture.

Installation works as follows. Through the inlet pipe of the automobile tank, the oil enters the tanker. An excessive vapor pressure is created in the tank. At the same time, the vapors along the flexible hose enter the section of the steam line and are pumped out with the help of the compressor through the check valve open under the compressor pressure into the main steam line connected to the additional tank. Vapors pass through a heat exchanger with a pumped cooling mixture, which is supplied from the tank through the pipeline of the cooling system using a pump. In this case, the main part of gaseous hydrocarbons as a result of cooling in the heat exchanger turns into a liquid state, and vapors that do not pass into the liquid are stratified by two partitions with holes of various diameters and absorbed by the low-octane component. The insoluble part of the gaseous hydrocarbons at the outlet of the tank is captured by the filter-absorber.

With "large" and "small" breaths with increasing pressure of the vapor space of the vertical tank, the working pressure breathing valve opens, and the vapor of oil products through the steam pipe enters the heat exchanger with the pumped cooling mixture. After the heat exchanger, a mixture of vapors with liquid oil enters the receiver and into the reservoir with the low-octane component.

The disadvantages of this installation are:

1. Low efficiency of the absorption of oil vapor by the low-octane component. High consumption of absorbent.

2. The inability to capture light fractions of gasoline without mixing with a low-octane component.

Known absorption installation for vapor recovery ASUR-PB [V.V. Anferov, V.G. Kovalenko, A.N. Rementsov. Technical equipment and personnel in oil products supply systems. Tutorial. M: MADI. 2006]. This unit is designed to capture and recover vapors of oil products at gas stations, oil depots, oil refineries. The installation is based on the principle of absorption - the absorption of hydrocarbons by a liquid absorbent. Diesel fuel is used as an absorbent. The installation consists of two units: absorption and refrigeration, as well as a control panel. In the absorption unit, vapor is captured by the cooled absorbent. The refrigeration unit is designed to cool the coolant and supply it to the absorption unit. The control panel provides automatic installation. Inside the absorption block on the bearings, a rotor is installed, which is a shaft with bearing discs mounted on it. Thin ring contact disks are installed on each carrier disk so that a certain gap is maintained between them. In the upper part of the absorption block there are inlet and outlet nozzles for vapors, in the lower for absorbent. The housing of the absorption unit is filled with absorbent material to a certain level.

Installation works as follows. When the rotor rotates on the surface of the contact disks immersed in diesel fuel, a thin absorbent film is formed. Air contaminated with oil vapor enters the absorption block through the inlet pipe, passes through the gaps between the contact disks, is cleaned by giving hydrocarbons to the absorbent, and leaves the absorption block through the outlet pipe. Absorbent flows towards the flow of the vapor-air mixture along the bottom of the block. The rotation of the rotor, partially immersed in diesel fuel, provides a constant replacement of the absorbent film. To reduce the temperature of the absorbent, the installation includes a refrigeration unit. The decrease in temperature of the absorbent occurs in the heat exchanger.

To capture the vapors from the tanks of cars using the ASUR-PB installation, the fuel dispensers are equipped with units for collecting oil vapor from the necks of the fuel tanks of automobiles. These are special dispensing taps with additional valves for collecting vapors, two-channel dispensing hoses for venting vapors into reservoirs, a unit for supplying vapors to the reservoir, special valves that balance fuel and vapor consumption. When refueling tanks of machines, the installation works as follows. Oil product vapors from car tanks are pumped out by a column unit through a dispensing tap, a two-channel dispensing sleeve, a steam line to the tank from which the cars are refueling.

The disadvantages of this installation are:

1. Large electric power consumption by refrigeration and absorption units and a unit for supplying vapors from automobile tanks.

2. High consumption of absorbent.

3. The inability to capture light fractions of gasoline without mixing with a low-octane component.

Also known installation of vapor recovery of petroleum products with periodic operation of the refrigeration unit at gas stations [Yu.A. Matveev et al. Utility Model Patent No. 141280 of 05/27/2014].

On a horizontal tank with standard equipment, in addition to the case of the breathing valve, a common piping line with a gate valve and a check valve is horizontally installed, which is connected to the main steam line connected to the buried tank. The recessed tank is equipped with a breathing valve, an activated charcoal filter-absorber and a device for receiving oil vapor, and is also half-filled with a low-octane component.

The main steam line passes the heat exchanger. The heat exchanger is equipped with cooling lines and connected to the refrigeration unit. For the purpose of turning on and off, the refrigeration unit is connected via a communication line to the corresponding relay. Also, the dispensing valve, which is inserted into the fuel tank of the car, is equipped with a two-channel dispensing sleeve connected to the fuel dispenser. Vapors of petroleum products through the hose are fed through the unit to the section of the steam line, and then through the low pressure check valve to a separate vapor collection tank, which is equipped with an appropriate pressure gauge. The manometer through a communication line is connected to the corresponding relay to turn on the refrigeration unit. Vapors of oil products pumped out of the tanks of the machines, due to the supply of the unit, accumulate in the tank up to a certain pressure, for which the high-pressure check valve is designed. Vapor pressure is recorded by the corresponding pressure gauge, which is connected by a communication line to the corresponding relay. The relay includes an electric motor connected by means of a coupling to a shaft on which centrifugal wheels are located. Also, the relay is connected by a communication line to the corresponding electric motor to open the valve.

Installation works as follows. Through the drain device, the oil enters the tank. The operator turns on the refrigeration unit. With increasing pressure, the reservoir breathing valve plate and the vapor rise through an open pipeline system, the non-return valve enters the main steam line connected to the additional tank. Vapors pass through a heat exchanger. In this case, the main part of gaseous hydrocarbons as a result of cooling becomes liquid, and vapors that have not passed into the liquid are absorbed by the low-octane component. The insoluble part of the gaseous hydrocarbons at the outlet of the tank through the breathing valve is captured by the filter-absorber. Vapors from car tanks are refilled with oil product during refueling. On a two-channel sleeve, with the help of the unit, through the section of the steam line and the low-pressure check valve, the vapor enters the vapor collection tank. Upon reaching a certain vapor pressure, the corresponding pressure gauge, through the relay, turns on the refrigeration unit to establish a given temperature regime, which should be in the range from minus 5 to minus 10 degrees Celsius. Vapors accumulate in the tank to the response pressure of the overpressure check valve. When the set pressure is reached, the corresponding manometer through the communication line and the corresponding relay includes an electric motor for rotating the shaft with centrifugal wheels. At the same time, through the communication line, the corresponding relay switches on the corresponding electric motor to open the vapor feed gate.

After opening the non-return valve of high pressure and the valve, the pairs of oil products through the steam pipe enter the heat exchanger with the set temperature regime. Then the mixture of vapors with liquid oil enters the receiving device and into the tank with a rotating shaft and centrifugal wheels. In the tank, oil vapor is absorbed by the low-octane component sprinkled throughout the volume.

The disadvantages of this installation are:

1. The inability to capture light fractions of gasoline without mixing with a low-octane component.

2. Low efficiency with “small” tank breathing.

Closest to this problem is the installation of vapor recovery of petroleum products with an additional reservoir for collecting vapors and a cooling system for ground vertical steel tanks [Yu.A. Matveev Yu.A. and other Patent for utility model No. 142402 dated 06/27/2014].

The proposed tank, which has standard equipment, is equipped with an additional steam line with a check valve and a valve that connects to a recessed horizontal steel tank. The tank is equipped with a valve, activated charcoal filter-absorber and a device for receiving oil vapor. The recessed tank is half filled with a low-octane component. An additional steam line underground passes through a heat exchanger with a cooling mixture. The cooling mixture from the tank is fed to the heat exchanger through the pipe of the cooling system using a pump. Also, the steam line through the section of the steam line with the corresponding valve is connected to an additional tank for collecting vapors. At the opening of the breathing valve of the working pressure, oil vapor is recorded by a manometer, which turns on the compressor through the communication line using the appropriate relay. Vapors of oil products are supplied through a steam pipeline to a section of the steam pipeline, and then through a low pressure check valve to an additional tank for collecting vapor. Vapors of oil products accumulate in the tank to a certain pressure. The vapor pressure in the section of the steam line after the check valve of the increased pressure is recorded by the corresponding pressure gauge, which is connected by a communication line to the corresponding relay. The relay includes an electric motor connected by means of a coupling to a shaft on which centrifugal wheels are located. Also, through the communication line, the corresponding relay includes a pump for supplying the cooling mixture through the heat exchanger.

Installation works as follows. When receiving fuel, the operator includes an electric motor for rotating the centrifugal wheels and a pump for supplying the cooling mixture to the heat exchanger. In order to catch the vapors during “big” breaths, the breathing valve opens, the non-return valve and through the steam line the vapors enter the heat exchanger with the pumped cooling mixture. In this case, the bulk of the fuel vapor goes into the liquid state, and the vapor that has not passed into the liquid is absorbed by the low-octane component. With "small" breaths, with an increase in the pressure of the vapor space of the tank, the breathing valve also opens, and oil vapor enters the steam line and section of the steam line. The flow of vapor into the steam line is recorded by a suitable pressure gauge, which includes a compressor. After the pressure in the steam line drops, the compressor automatically shuts off. With the help of a compressor, vapors enter an additional reservoir for collecting vapors. The flow of vapor into the section of the steam line after the high pressure check valve is recorded by a manometer, which includes an electric motor for rotating the shaft with centrifugal wheels. Also, through the communication line, the relay includes a pump for supplying the cooling mixture through the heat exchanger. After opening the check valve of the increased pressure, oil product vapors enter the heat exchanger with the pumped cooling mixture. Then the mixture of vapors with liquid oil enters the receiving device and into the tank with a rotating shaft and centrifugal wheels. In the tank, oil vapor is absorbed by the low-octane component. After closing the high-pressure check valve, the operator opens the valve, and the oil vapor due to the increased pressure in a similar way enters the buried tank. The disadvantages of this installation are:

1. The inability to capture light fractions of gasoline without mixing with a low-octane component.

2. Low efficiency of the heat exchanger.

3. High consumption of the cooling mixture.

The present invention allows to solve the problem of increasing the efficiency of trapping vapors of petroleum products, when receiving and storage in vertical ground tanks.

The solution to this problem is achieved by the fact that the breathing valves of the vertical steel tank are equipped with a steam line connected to the vapor collection tank and with a buried two-section tank, while the steam line is equipped with a compressor, manometers, valves and check valves, as well as the fact that the system is equipped with a refrigeration unit with cooling element in a buried tank. At the same time, the low-octane component is poured into the first section of the recessed tank and it is equipped with a shaft with rotating wheels and a cooling element, and A-76 gasoline is poured into the second section and it is equipped with a steam supply line. Also, sections of steam pipelines before and after the vapor collection tank are equipped with non-return valves with different opening pressures, and the manometers on the steam pipelines are configured to turn on the compressor, refrigeration unit, electric motor, and vapor recovery valve.

These signs are essential for solving the problem of the invention, since the efficiency of trapping vapors of oil products in tanks is increased, the consumption of absorbent and consumed electric energy is reduced, and savings are also made by trapping light fractions of marketable gasolines with their subsequent use as marketable gasolines.

It should be noted that in order to turn vapors from “small” breaths into a liquid, it is necessary to lower the temperature below the boiling point of gasolines, that is, less than 35 degrees Celsius. To turn vapors from “big” breaths into a liquid, it is necessary to lower the temperature to values from minus 5 to minus 10 degrees Celsius. An absorbent (low-octane component) is also used.

The invention is illustrated by drawings (figure 1, figure 2), which depict: sections of the tank with the installation of vapor recovery, as well as a section of a recessed two-section with a refrigeration unit.

The proposed tank 1, having a receiving and distributing nozzles 2, a pipe for receiving and dispensing oil products 3, valves 4, light and metering hatches 5.6, ventilation pipe 7, a pressure breathing valve 8, a manhole 9, a working pressure breathing valve 10, an additional steam line 11 is equipped with a non-return valve 12 and valves 13, which is connected to a recessed two-section steel tank 14. The first section of the tank is equipped with a valve 15, an activated charcoal filter 16 and a device A receiving oil vapor 17 which has two walls with holes of different diameters for crushing 18.19 vapor bubbles. This section of the tank is half-filled with a low-octane component (diesel fuel) 20 and is designed to capture vapors during "large" breaths. To catch the vapors during “small” breaths, the second section of the tank is poured with summer A-76 gasoline 21, while a steam line 11 is brought into this section, which drops below the level of gasoline. An additional steam line 11 passes underground 22 and has a serpentine-shaped section to reduce the vapor pressure of oil products. The steam line is connected to the refrigeration unit 23. The refrigeration unit is equipped with a cooling element 24 located in the reservoir 14. Also, the steam line 11 is connected through a section of the steam line 25 with the corresponding valves 13 to a separate reservoir for collecting vapors 26. When oil is opened, the working pressure breathing valve 10 is registered accordingly manometer 27. Inside the manometer, a contact plate is installed at a certain value. When the gauge needle contacts the plate through the communication line 28 using the corresponding relay 29, the compressor 30 is turned on. The vapor of oil products is supplied through the steam line 11 to the section of the steam line 25 via the compressor 30 and then through a low pressure check valve 31 to a separate vapor collection tank 26 . When the pressure in the steam line drops, the compressor switches off. Vapors of oil products pumped out through the steam line 11 and the section of the steam line 25 due to the supply of the compressor 30 are accumulated in the tank 26 to a certain pressure, for which the high-pressure check valve 32 is designed. The vapor pressure in the pipeline section 25 after the check valve 32 is registered by the corresponding pressure gauge 27, which also equipped with a contact plate mounted at a specific value. The pressure gauge is connected by a communication line 28 to the corresponding relay 29. When the pressure gauge’s arrow contacts the plate through the communication line 28 and the corresponding relay 29, the electric motor 33 is turned on, coupled via a coupling 34 to the shaft 35, on which the centrifugal wheels 36 are located. The shaft 35 is installed in the first section reservoir 14 on bearings. Also, through the communication line 28 and the corresponding relay 29 from the pressure gauge, the refrigeration unit 24 is turned on and the vapor exhaust valve 37 opens.

The invention works as follows. Through the intake pipe 3, the oil enters the tank 1. In this case, the fuel level begins to increase, and accordingly the volume of the vapor space decreases. In order to catch the vapors during “big” breaths, the breathing valve 10 opens, the non-return valve 12 and the vapors enter the steam line 11. In the steam line the vapors are registered with the corresponding pressure gauge 27, which is connected through the communication line 28 and the corresponding relay 29 to the compressor 30. When the pressure gauge’s arrow is in contact with the plate through the communication line 28 using the appropriate relay 29, the compressor 30 is turned on. After the pressure drops in the steam line 11, the compressor is automatically turned off. In order to prevent vapor from entering the two-section tank, the corresponding valve 13 on the steam line 11 is closed.

Using the compressor 30 through the section of the steam pipe 28 and the low pressure check valve 31, the pairs enter the vapor collection tank 26, where they accumulate to the pressure of the high pressure check valve 32.

The flow of vapor into the section of the steam line 25 after the overpressure check valve 32 is registered by the corresponding pressure gauge 27. When the pressure gauge needle contacts the plate, the cooling unit 23 with the cooling element 24 is turned on via the corresponding relay 29 to lower the temperature in the tank 14. Also opens the valve 37 and the motor 33 is turned on, which starts to rotate the shaft 35 with the centrifugal wheels 36 to mix the cooled low-octane component throughout the volume of the first section reservoir 14. After closing the check valve high pressure through the valve 37 pairs of oil due to high pressure in a similar way enter the first section of the tank 14.

In this case, the main part of the fuel vapor as a result of cooling becomes liquid, and the vapor that has not passed into the liquid is stratified by two partitions with holes of various diameters 18.19 and absorbed by the low-octane component 20. The insoluble part of the vapor at the outlet of the reservoir section 14 when the valve is activated 15 is captured by the filter-absorber 16. After pumping the oil product, the operator turns off the refrigeration unit 23, the electric motor 33 closes the corresponding valves 13 of the section of the steam pipe 25, and akryvaet valve 37.

With "small" breaths, with increasing pressure of the vapor space of the tank, the breathing valve 10 also opens and oil product vapors enter the steam line 11. Then, when the corresponding valves are open 13 on the steam line 11 and the valves are closed on sections of the steam supply, they enter the second section of the tank 14 with gasoline A-76.

In this section of the tank 14, the conversion of fuel vapor into liquid occurs due to lower temperatures and the absorption of oil vapor by A-76 gasoline. The conversion of oil vapor into liquid occurs due to the lower temperature in the underground reservoir compared to the vapor evaporation temperature during “small” breaths. The temperature in the underground reservoir, even in summer, does not exceed 15-18 degrees Celsius.

Periodic operation of the electric motor and the refrigeration unit significantly reduce energy consumption. In this case, a mixture of light fractions of petroleum products with A-76 gasoline can be used to add normal-80 and A-76 brands to marketable gasolines. Also, a mixture of diesel fuel and gasoline can be handed over for processing or used as a solvent.

Claims (4)

1. A vapor recovery system for receiving and storing oil products at oil depots, including a steam line, a vapor collection tank, a compressor, manometers, check valves, communication lines, a relay, an underground tank, an electric motor, a shaft with centrifugal wheels, a low-octane component, characterized in that the breathing valves of the vertical steel tank are equipped with a steam line connected to the vapor collection tank and with a recessed two-section tank, while the steam line is equipped with a compressor, manometers, a valve and check valves and, and in that the system is equipped with a refrigeration unit with a cooling element in the submerged tank. 2. The system according to claim 1, characterized in that the low-octane component is poured into the first section of the recessed tank and it is equipped with a shaft with rotating wheels and a cooling element, and A-76 gasoline is poured into the second section and it is equipped with a steam supply line. 3. The system according to claim 1, characterized in that the sections of the steam lines before and after the vapor collection tank are equipped with check valves with different opening pressures. 4. The system according to claim 1, characterized in that the pressure gauges on the steam line are configured to be switched on by means of a relay of a compressor, a refrigeration unit, an electric motor and a vapor recovery valve.

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