Oil gas condensation recovery device for oil gas storage tank breather valve outlet

Abstract

This invention discloses an oil and gas condensation recovery device for the outlet of a breather valve in an oil and gas storage tank, belonging to the field of oil and gas storage technology. It includes an oil storage tank, with a breather valve at the upper end. A cover is provided around the outlet of the breather valve, and a cavity is located inside the lower end of the cover. A nozzle is fixedly connected to the upper end of the cover, and a collection tray is located at the lower end. A protective filter screen is installed between the collection tray and the cover. The lower end of the collection tray is connected to an enrichment separator via a collection pipe. The lower end of one side of the enrichment separator is connected to the nozzle via a cooling pipe. A cooling heat exchanger is installed on the cooling pipe. The collection pipe and the cooling pipe form a circulation loop containing a cooling circulating medium. The advantages of this invention compared to existing technologies are: it meets the requirement of maintaining pressure balance between the breather valve and the atmospheric environment, and it has lower operating difficulty and lower operating costs.

Description

Technical Field

[0001] This invention relates to the field of oil and gas storage technology, specifically to an oil and gas condensation recovery device for the outlet of the breather valve of an oil and gas storage tank. Background Technology

[0002] Gasoline, petroleum, and other petroleum products are typically stored in large oil and gas storage tanks equipped with sealed floating roofs. However, due to their large size and poor sealing performance, these floating roofs create a space rich in volatile light hydrocarbons (oil and gas) in the upper part between the floating roof and the tank top. The oil and gas content within this space is related to the pressure and temperature of the surrounding environment, and the partial pressure of the oil and gas components approaches their saturation pressure.

[0003] This space is connected to the external atmosphere via a breather valve. When the oil and gas storage tank discharges stored oil, the floating roof descends, creating a slight negative pressure in the upper space. The breather valve opens, allowing air to enter the upper space. This reduces the partial pressure of the oil and gas, causing the volatile light hydrocarbon components to continuously evaporate into the upper space until saturation pressure is reached. When the storage tank receives oil, the floating roof rises, creating a positive pressure in the upper space. The breather valve opens, and the oil and gas in the upper space begin to be discharged, resulting in the release of volatile light hydrocarbon components into the atmosphere, causing resource waste and atmospheric pollution. Daily temperature changes also cause pressure changes within the space. When the ambient temperature decreases, the ambient pressure decreases, causing the breather valve to draw in air; when the ambient temperature rises, the ambient pressure increases, causing the breather valve to discharge oil and gas.

[0004] Currently, oil and gas processing equipment on the market is mainly used in the transportation and delivery stages, while there are relatively few technologies for oil and gas recovery and purification in the storage stage. The very few projects that treat oil and gas emitted from the breather valves of large oil and gas storage tanks are also applications of modified adsorption and desorption closed-loop processes. The closed-loop processes adopted cannot meet the requirements of maintaining the pressure balance between the breather valve and the atmospheric environment. Existing solutions generally use nitrogen or other inert gases as intermediate media to compensate for this deficiency. In general, this approach increases the difficulty of operating the process system and the operating costs. Summary of the Invention

[0005] The present invention aims to solve the technical problems mentioned in the background section above, and provides an oil and gas condensation recovery device for the outlet of the breather valve of an oil and gas storage tank that can meet the requirements of maintaining the pressure balance between the breather valve and the atmospheric environment, and has low operation difficulty and low operating cost.

[0006] The technical solution provided by this invention is as follows: an oil and gas condensation recovery device for the outlet of a breather valve in an oil and gas storage tank, comprising an oil storage tank, a breather valve at the upper end of the oil storage tank, a cover covering the outlet of the breather valve, a cover cavity inside the lower end of the cover, a nozzle fixedly connected to the upper end of the cover, a liquid collection tray at the lower end of the cover, a protective filter screen between the liquid collection tray and the cover, the lower end of the liquid collection tray being connected to an enrichment separator through a collection pipe, the lower end of one side of the enrichment separator being connected to the nozzle through a cooling pipe, a cooling heat exchanger being provided on the cooling pipe, the collection pipe and the cooling pipe forming a circulation loop, and a cooling circulation medium being provided inside the loop.

[0007] Furthermore, a first baffle and a second baffle are vertically fixedly connected to the inner side wall of the enrichment separator. A gap is provided between the first baffle and the bottom inner wall of the enrichment separator. The second baffle is located at one end of the enrichment separator near the cooling pipe and is arranged parallel to the first baffle. The upper end of the second baffle is higher than the opening height of the cooling pipe inside the enrichment separator and lower than the upper end of the side wall of the enrichment separator. Its lower end is closed and abuts against the lower end wall inside the enrichment separator.

[0008] Furthermore, an external discharge pipe is fixedly connected horizontally at the upper end of the enrichment separator, and the height of the external discharge pipe at the opening inside the enrichment separator is higher than the upper end of the second baffle.

[0009] Furthermore, the filtration area of ​​the protective filter is larger than the area of ​​the breathing valve outlet.

[0010] Furthermore, the cooling outlet temperature of the cooling circulating fluid at the outlet of the cooling heat exchanger is controlled at the freezing point temperature T-5℃, and the cooling outlet temperature of the cooling circulating fluid at the outlet of the cooling heat exchanger is controlled at the ambient temperature T-10℃.

[0011] Furthermore, the median particle size of the nozzle spray is 1000μm to 1500μm, the number of droplets ≥500μm is greater than 95%, the coverage of the nozzle spray is not less than 150%, and the spray intensity of the nozzle is positively correlated with the exhaust intensity of the breather valve, which is not less than 1m3 / m2h.

[0012] Furthermore, the connection port between the collection pipe and the enrichment separator is located on the inside side of the enrichment separator away from the second baffle. The cooling pipe is high in the middle and low at both ends in a section inside the enrichment separator, and its highest point is lower than the highest point of the second baffle.

[0013] Furthermore, the cooling circulating fluid medium of this device is selected based on the different volatile light hydrocarbon components to be recovered, the ambient temperature conditions, and the recovery and enrichment requirements.

[0014] Furthermore, a pneumatic circulation pump is installed on the cooling pipe between the cooling heat exchanger and the enrichment separator. The start and stop of the pneumatic circulation pump are controlled according to the exhaust action of the breather valve.

[0015] Furthermore, the start and stop of the pneumatic circulation pump are controlled based on the difference between the environmental pressure in the space at the top of the oil storage tank and the external atmospheric environment.

[0016] The advantages of this invention compared to the prior art are: by using a cooling circulation pipeline to ensure that the breather valve of the oil and gas storage tank can operate normally, the invention achieves the condensation and recovery of oil-rich gas discharged from the breather valve of the oil storage tank, while having lower operating costs and simpler operation.

[0017] The beneficial effects of this invention are as follows: 1. It can effectively recover the oil and gas resources discharged from the breather valve and reduce the emission of volatile light hydrocarbon components discharged from the breather valve; 2. The breather valve of the large oil storage tank with a sealed floating plate is directly connected to the atmospheric environment, which is safe and reliable in operation, convenient in installation, and simple in maintenance; 3. The operation is synchronized with the discharge action of the breather valve of the large oil storage tank with a sealed floating plate, which is simple in operation, low in construction cost, and wide in applicability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an oil and gas condensation and recovery device at the outlet of the breather valve of an oil and gas storage tank according to an embodiment of the present invention.

[0019] Figure 2 for Figure 1 The enlarged schematic diagram of the enrichment separator section shown is shown.

[0020] In the attached diagram: 1. Oil storage tank; 2. Breathing valve; 3. Cover; 4. Nozzle; 5. Collection tray; 6. Protective filter; 7. Collection pipe; 8. Enrichment separator; 81. First baffle; 82. Second baffle; 83. Outlet pipe; 9. Cooling pipe; 10. Cooling heat exchanger; 11. Pneumatic circulation pump. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings.

[0022] Combination Figure 1 , Figure 2As shown, an oil and gas condensation recovery device for the outlet of a breather valve in an oil and gas storage tank includes an oil storage tank 1. A breather valve 2 is located at the upper end of the oil storage tank 1. A cover 3 surrounds the outlet of the breather valve 2. A cavity is located inside the lower end of the cover 3. A nozzle 4 is fixedly connected to the upper end of the cavity, and a collection tray 5 is located at its lower end. A protective filter 6 is installed between the collection tray 5 and the cover 3. The filtration area of ​​the protective filter 6 is larger than the area of ​​the outlet of the breather valve 2. The median particle size sprayed by the nozzle 4 is 1000μm to 1500μm, with the number of droplets ≥500μm exceeding 95%. The coverage rate of the nozzle 4 is not less than 150%. The spray intensity of the nozzle 4 is positively correlated with the exhaust intensity of the breather valve 2, and is not less than 1 m³ / m²h.

[0023] The lower end of the liquid collection tray 5 is connected to the enrichment separator 8 through the collection pipe 7. The collection pipe 7 connects to the left side of the inside of the enrichment separator 8. A first baffle 81 and a second baffle 82 are vertically fixedly connected to the inner side wall of the enrichment separator 8. A gap is provided between the first baffle 81 and the bottom inner wall of the enrichment separator 8. The second baffle 82 is located to the right of the first baffle 81 and is parallel to the first baffle 81. The upper end of the second baffle 82 is higher than the opening height of the cooling pipe 9 inside the enrichment separator 8 and lower than the upper end of the side wall of the enrichment separator 8. Its lower end is closed and abuts against the lower inner wall of the enrichment separator 8.

[0024] An external discharge pipe 83 is fixedly connected horizontally at the upper end of the enrichment separator 8. The height of the external discharge pipe 83 at the opening inside the enrichment separator 8 is higher than the upper end of the second baffle 82.

[0025] The lower right end of the enrichment separator 8 is connected in sequence to the pneumatic circulation pump 11, the cooling heat exchanger 10, and the nozzle 4 via a cooling pipe 9. The cooling pipe 9 inside the enrichment separator 8 is higher in the middle and lower at both ends, with its highest point slightly lower than the highest point of the second baffle 82, in order to maintain a stable liquid level inside the enrichment separator 8. The collection pipe 7 and the cooling pipe 9 form a circulation loop, which contains a cooling circulation medium. This cooling circulation medium is selected according to the different volatile light hydrocarbon components to be recovered, the ambient temperature conditions, and the recovery and enrichment requirements. The pneumatic circulation pump 11 can be started and stopped based on the exhaust action of the breather valve 2, or it can be started and stopped based on the difference between the ambient pressure in the top space of the oil storage tank 1 and the external atmospheric environment. All components, including the pneumatic circulation pump 11, the cooling heat exchanger 10, and the connecting pipes and valves, are designed with full consideration of safe operation requirements and are explosion-proof.

[0026] The outlet temperature of the cooling circulating fluid at the outlet of heat exchanger 10 is controlled at the freezing point temperature T - 5℃, and the outlet temperature of the cooling circulating fluid at the outlet of heat exchanger 10 is controlled at the ambient temperature T - 10℃.

[0027] In specific implementation of this invention:

[0028] Combination Figure 1 , Figure 2 As shown, when the pressure in the sealed space formed by the upper part of the sealed floating plate and the top of the oil storage tank 1 increases, the breather valve 2 opens and discharges gas containing a large amount of volatile light hydrocarbon components (oil gas). At this time, the pneumatic circulation pump 11 works to pump the circulating washing liquid to the cooling heat exchanger 10. The circulating washing liquid is cooled to a low temperature after passing through the cooling heat exchanger 10. It sprays the gas (containing oil gas) discharged from the breather valve 2 through the nozzle 4. The gas discharged from the breather valve 2 comes into full contact with the low temperature washing liquid spray for heat exchange. The gas temperature decreases and the condensable gas, including the volatile light hydrocarbon components, is released and condensed into droplets. It changes from a gaseous state to a liquid state and is collected by the liquid collection plate along with the sprayed droplets.

[0029] Non-condensable gases in the gas discharged from the breather valve 2 are released into the ambient atmosphere through the protective filter 6. The fine low-temperature circulating droplets and oil and gas condensate droplets carried in the non-condensable gases are intercepted by the protective filter 6 and collected by the accumulating liquid tray. The circulating washing liquid collected by the accumulating liquid tray and the condensate droplets flow into the enrichment separator 8. The condensate droplets collected in the enrichment separator 8 are enriched in the upper layer and collected uniformly through the external discharge pipe 83 to achieve resource recovery.

[0030] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An oil and gas condensation recovery device for the outlet of a breather valve in an oil and gas storage tank, comprising an oil storage tank (1), wherein a breather valve (2) is provided at the upper end of the oil storage tank (1), characterized in that: The outlet of the breathing valve (2) is covered with a cover (3). The lower end of the cover (3) is provided with a cover cavity. The upper end of the cover (3) is fixedly connected with a nozzle (4). The lower end of the cover (3) is provided with a liquid collection plate (5). A protective filter screen (6) is provided between the liquid collection plate (5) and the cover (3). The lower end of the liquid collection plate (5) is connected to an enrichment separator (8) through a collection pipe (7). The lower end of one side of the enrichment separator (8) is connected to the nozzle (4) through a cooling pipe (9). A cooling heat exchanger (10) is provided on the cooling pipe (9). The collection pipe (7) and the cooling pipe (9) form a circulation loop, which contains a cooling circulation medium. The enrichment separator (8) has a first baffle (81) and a second baffle (82) vertically fixedly connected to its inner side wall. The first baffle (81) has a gap between it and the bottom inner wall of the enrichment separator (8). The second baffle (82) is located inside the enrichment separator (8) near the cooling pipe (9) and is parallel to the first baffle (81). The upper end of the second baffle (82) is higher than the opening height of the cooling pipe (9) inside the enrichment separator (8) and lower than the upper end height of the side wall of the enrichment separator (8). Its lower end is closed and abuts against the lower end wall inside the enrichment separator (8).

2. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: An external discharge pipe (83) is fixedly connected horizontally at the upper end of the enrichment separator (8). The height of the external discharge pipe (83) at the opening inside the enrichment separator (8) is higher than the upper end of the second baffle (82).

3. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: The filtration area of ​​the protective filter (6) is larger than the area of ​​the outlet of the breathing valve (2).

4. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: The cooling outlet temperature of the cooling circulating liquid at the outlet of the cooling heat exchanger (10) is controlled at the ambient temperature T-10℃.

5. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: The median particle size sprayed by the nozzle (4) is 1000μm to 1500μm, and the number of droplets ≥500μm is greater than 95%. The coverage of the nozzle (4) is not less than 150%. The spray intensity of the nozzle (4) is positively correlated with the exhaust intensity of the breather valve (2), and is not less than 150%. .

6. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: The connection port between the collection pipe (7) and the enrichment separator (8) is located on the inside side of the enrichment separator (8) away from the second baffle (82). The cooling pipe (9) is high in the middle and low at both ends in a section inside the enrichment separator (8), and its highest point is lower than the highest point of the second baffle (82).

7. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: The cooling circulating fluid medium of this device is selected based on the different volatile light hydrocarbon components to be recovered, the ambient temperature conditions, and the recovery and enrichment requirements.

8. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 1, characterized in that: A pneumatic circulation pump (11) is provided on the cooling pipe (9) between the cooling heat exchanger (10) and the enrichment separator (8). The start and stop of the pneumatic circulation pump (11) are controlled according to the exhaust action of the breather valve (2).

9. The oil and gas condensate recovery device for the outlet of the breather valve of an oil and gas storage tank according to claim 8, characterized in that: The start and stop of the pneumatic circulating pump (11) are controlled based on the difference between the environmental pressure in the top space of the oil storage tank (1) and the external atmospheric environment.

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