A system for recovering light hydrocarbons in stages

Abstract

The application discloses a system for recovering light hydrocarbon in sections, which is arranged on a normal-pressure storage tank and comprises a gas collecting structure arranged in the normal-pressure storage tank and used for collecting light hydrocarbon gas in the normal-pressure storage tank and conveying the light hydrocarbon gas; a pressure stabilizing structure connected with the normal-pressure storage tank through a pipeline and used for introducing the gas into the normal-pressure storage tank and separating the gas and liquid; a liquid storage structure connected with the pressure stabilizing structure and used for storing the separated liquid in the pressure stabilizing structure; a regulating structure arranged on the pressure stabilizing structure and used for warning the pressure in the pressure stabilizing structure through the gas; a liquefying device connected with the pressure stabilizing structure and used for introducing the gas in the pressure stabilizing structure and liquefying the gas; and a gas input structure with an input end connected with the liquefying device and an output end connected with the pressure stabilizing structure and used for introducing the gas in the liquefying device into the pressure stabilizing structure.

Description

Technical Field

[0001] This disclosure relates to the field of gas collection systems for oil storage tanks, and more particularly to a system for the staged recovery of light hydrocarbons. Background Technology

[0002] With industrial development, the demand for petroleum in various fields is increasing. However, during the storage process, a large amount of light hydrocarbon gas is generated as the outside temperature of the oil storage tank changes.

[0003] Currently, oil storage tanks use internal floating roofs that float on the surface of the liquefied oil. These roofs rise and fall with the oil level, reducing the generation of light hydrocarbon gases. However, this method cannot completely prevent the generation of light hydrocarbon gases due to changes in the surrounding environment. These gases accumulate in the space above the tank, posing a fire hazard. Furthermore, since the tanks cannot be completely sealed, the release of these gases into the atmosphere causes air pollution and significant resource waste. Therefore, it is necessary to address the issue of light hydrocarbon gas recovery and utilization. Summary of the Invention

[0004] The purpose of this disclosure is to provide a system for the staged recovery of light hydrocarbons, which solves the problems of waste, pollution, and insufficient utilization of light hydrocarbon gases in existing atmospheric pressure storage tanks.

[0005] To achieve the above objectives, a first aspect of this disclosure provides a system for the staged recovery of light hydrocarbons, for installation on an atmospheric pressure storage tank, comprising:

[0006] A gas collection structure is provided inside the atmospheric pressure storage tank to collect and transport light hydrocarbon gases from the atmospheric pressure storage tank.

[0007] A pressure stabilizing structure is connected to the atmospheric pressure storage tank via a pipeline to introduce gas from the atmospheric pressure storage tank and perform gas-liquid separation.

[0008] A liquid storage structure, which is connected to the pressure stabilizing structure, is used to store the liquid separated within the pressure stabilizing structure;

[0009] A control structure is provided on the pressure stabilizing structure for indicating the pressure inside the pressure stabilizing structure via gas.

[0010] A liquefaction device, which is connected to the pressure stabilizing structure, is used to introduce gas from the pressure stabilizing structure and liquefy the gas.

[0011] A gas input structure is provided, wherein the input end of the gas input structure is connected to the liquefaction device, and the output end of the gas input structure is connected to the pressure stabilizing structure, for introducing the gas from the liquefaction device into the pressure stabilizing structure.

[0012] In some embodiments, the gas collection structure includes a floating plate, a sealing airbag, a connecting block, and a telescopic tube;

[0013] The floating roof floats on the oil surface inside the atmospheric pressure storage tank. The diameter of the floating roof is smaller than the inner diameter of the atmospheric pressure storage tank. An annular protrusion is provided at the edge of the floating roof away from the oil surface. A through hole is provided on the side wall of the floating roof along the diameter direction. The sealing airbag opens towards the oil surface. One side of the sealing airbag is connected to the annular protrusion, and the other side of the sealing airbag abuts against the inner side wall of the atmospheric pressure storage tank. The telescopic pipe is connected to the connecting block, which is connected to the surface of the floating roof and the through hole.

[0014] In some embodiments, the pressure stabilizing structure includes a gas storage tank, a top cover, and a pressure cylinder;

[0015] The gas storage tank is connected to the atmospheric pressure storage tank via a pipeline. The gas storage tank is connected to the liquid storage structure, the gas storage tank is connected to the gas output structure, and the gas storage tank is connected to the gas input structure. One end of the gas storage tank is open.

[0016] An annular groove is provided on the end face of the opening end of the gas storage tank. The annular groove surrounds the opening of the gas storage tank and is concentric with the end face of the gas storage tank. The end face of the annular groove and the end face of the gas storage tank are on the same horizontal line. Sealing liquid is contained in the annular groove.

[0017] The top cover is fixedly connected to one end face of the pressure cylinder, the pressure cylinder is placed in the annular groove, and the other end face of the pressure cylinder is immersed in the sealing liquid.

[0018] In some embodiments, the liquid storage structure includes a liquid storage tank, a first liquid outlet valve, and a first liquid level gauge. The liquid storage tank is located at the lower end of the gas storage tank and is connected to the gas storage tank. The first liquid outlet valve is disposed at the bottom end of the liquid storage tank and is used to discharge the liquid in the liquid storage tank. The first liquid level gauge is an L-shaped long tube and is connected to the outer wall of the liquid storage tank to display the amount of liquid in the liquid storage tank.

[0019] In some embodiments, the control structure includes a first pulley, a second pulley, a lifting rope, a gravity block, and a limiting rod;

[0020] One end of the lifting rope is connected to the top cover, the first pulley is located on the side of the top cover away from the pressure cylinder, the second pulley is located on the same horizontal plane as the axis of the first pulley, and the other end of the lifting rope is connected to the gravity block.

[0021] The limiting rod is provided with a high-position warning plate and a low-position warning plate. The high-position warning plate and the low-position warning plate are arranged parallel to each other. The limiting rod is arranged on the side parallel to the side wall of the gravity block. The gravity block is arranged between the high-position warning plate and the low-position warning plate.

[0022] In some embodiments, the control structure further includes a first position sensor, a second position sensor, and a controller;

[0023] The first position sensor is disposed on the high-position warning plate and is used to monitor the first position information between the gravity block and the high-position warning plate;

[0024] The second position sensor is disposed on the low-position warning plate and is used to monitor the second position information between the gravity block and the low-position warning plate;

[0025] The controller is electrically connected to the first position sensor, the second position sensor, the gas input structure, and the liquefaction device, respectively. It receives first and second position information monitored by the first and second position sensors, and controls the operation of the gas input structure and the liquefaction device based on the first and second position information.

[0026] In some embodiments, the liquefaction device includes a gas output structure and a pressure structure. The gas output structure includes an output pipe, a gas pump, a gas-liquid separation chamber, a one-way valve, and a first heat sink. One end of the output pipe is connected to the gas storage tank, and the other end of the output pipe is connected to the pressure structure.

[0027] The air pump is mounted on the output pipe and connected to the output pipe. The air pump is used to accelerate the delivery of gas in the output pipe. The controller is electrically connected to the air pump. A second liquid outlet valve is provided at the bottom of the gas-liquid separation chamber. The second liquid outlet valve is used to discharge the liquid in the gas-liquid separation chamber. The gas-liquid separation chamber is mounted on the output pipe and connected to the output pipe. A one-way valve is mounted on the output pipe. The first heat sink is wrapped around the output pipe and is located at the end of the output pipe that connects to the pressure structure.

[0028] In some embodiments, the pressure structure includes a pressure tank, a liquid-blocking plate, a pressure gauge, a third liquid outlet valve, and a second liquid level gauge. The other end of the output pipe is connected to the pressure tank, and the pressure tank is connected to the gas input structure. The liquid-blocking plate is disposed inside the pressure tank. The liquid-blocking plate includes an inclined portion and an inverted V portion. The inclined portion is disposed on the inner sidewall of the pressure tank and extends from the inner sidewall of the pressure tank towards the central axis of the pressure tank. The inclined portion is inclined towards the bottom of the pressure tank, and the inverted V portion is disposed on the side of the inclined portion near the bottom of the pressure tank. The inclined portion and the inverted V portion are fixedly connected and have a gap.

[0029] The pressure gauge is installed on the outer wall of the pressure tank and is electrically connected to the controller. The third liquid outlet valve is installed at the bottom of the pressure tank and is used to discharge the liquid in the pressure tank. The second liquid level gauge is an L-shaped long tube and is installed on the outer wall of the pressure tank to display the amount of liquid in the pressure tank.

[0030] In some embodiments, multiple liquefaction devices are arranged sequentially, with one end of the output pipe of the first liquefaction device connected to the gas storage tank and the other end connected to the pressure tank of the first liquefaction device, and the two pressure tanks of two adjacent liquefaction devices being connected to each other through the output pipe;

[0031] The pressure tank at the end is provided with an exhaust valve at its top, and the pressure tank adjacent to the end pressure tank is connected to the input end of the gas input structure.

[0032] In some embodiments, the gas input structure includes an input pipe, a second heat sink, and an input valve. The input end of the input pipe is connected to the pressure tank adjacent to the pressure tank at the end of the input pipe, and the output end of the input pipe is connected to the gas storage tank. The second heat sink is wrapped around the input pipe and is disposed at the end of the input pipe connected to the pressure tank. The input valve is disposed on the input pipe and is used to open or close the input pipe. The controller is electrically connected to the input valve.

[0033] By adopting the above technical solution, when the external temperature of the petroleum in the atmospheric pressure storage tank rises, a large amount of light hydrocarbon gas is generated and transported from the gas collection structure to the pipeline and enters the pressure stabilizing structure. A portion of the light hydrocarbon gas is converted into liquid in the pressure stabilizing structure and flows into the liquid storage structure. When the gas in the pressure stabilizing structure reaches its limit, the control structure can start the liquefaction device, allowing the gas in the pressure stabilizing structure to enter the liquefaction device, which then liquefies and stores the light hydrocarbon gas for the purpose of collecting it.

[0034] When the external temperature of the atmospheric pressure storage tank decreases, the amount of light hydrocarbon gas present in it decreases, causing the gas in the pressure stabilizing structure to be drawn back. As the amount of gas in the pressure stabilizing structure decreases, when the amount of gas reduced in the pressure stabilizing structure reaches a limit, the gas input structure opens, transporting the unliquefied light hydrocarbon gas in the liquefaction unit to the pressure stabilizing structure, and then from the pressure stabilizing structure to the gas collecting structure. Finally, the gas collecting structure transports the light hydrocarbon gas back to the atmospheric pressure storage tank to stabilize the pressure of the atmospheric pressure storage tank.

[0035] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0036] The accompanying drawings are provided to further understand the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof.

[0037] In the attached diagram:

[0038] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0039] Figure 2 This is a partial schematic diagram of the voltage stabilizing structure and the regulation structure of the present invention;

[0040] Figure 3 This is a partial schematic diagram of the liquefaction device and gas input structure of the present invention;

[0041] Figure 4 This is a partial schematic diagram of the atmospheric pressure storage tank and gas collection structure of the present invention;

[0042] Figure 5 This is a schematic diagram of the process for controlling the liquefaction device and gas input structure using the regulation structure of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Atmospheric pressure storage tank; 10. Gas collection structure; 11. Floating roof; 12. Through hole; 13. Annular protrusion; 14. Sealing airbag; 15. T-pipe; 16. Telescopic pipe; 2. Pressure stabilizing structure; 21. Gas storage tank; 22. Sealing fluid; 23. Annular groove; 24. Pressure cylinder; 25. Top cover; 3. Liquid storage structure; 31. Liquid storage tank; 32. First liquid outlet valve; 33. First liquid level gauge; 4. Control structure; 41. First pulley; 42. Lifting rope; 43. Second pulley; 44. Gravity block; 45. Limiting rod; 451. First position sensor; 452. High-level warning plate; 453. Second position sensor; 454. Sensor; 455. Low-level warning plate; 456. Controller; 5. Liquefaction device; 51. Gas output structure; 511. Output pipe; 512. Air pump; 513. Gas-liquid separation chamber; 514. Check valve; 515. First heat sink; 516. Second liquid outlet valve; 52. Pressure structure; 521. Pressure gauge; 522. Liquid blocking plate; 5221. Inverted V-shaped section; 5222. Inclined section; 523. Second liquid level gauge; 524. Pressure tank; 525. Third liquid outlet valve; 526. Gas outlet valve; 6. Gas input structure; 61. Second heat sink; 62. Input pipe; 63. Input valve. Detailed Implementation

[0045] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0046] This disclosure provides a system for the staged recovery of light hydrocarbons, for installation on an atmospheric pressure storage tank 1, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the system includes: a gas collection structure 10 installed inside an atmospheric pressure storage tank 1 for collecting and transporting light hydrocarbon gas from the atmospheric pressure storage tank 1; a pressure stabilizing structure 2 connected to the atmospheric pressure storage tank 1 via a pipeline for introducing gas from the atmospheric pressure storage tank 1 and performing gas-liquid separation; a liquid storage structure 3 connected to the pressure stabilizing structure 2 for storing the liquid separated within the pressure stabilizing structure 2; a regulating structure 4 installed on the pressure stabilizing structure 2 for signaling the internal pressure of the pressure stabilizing structure 2 via gas; a liquefaction device 5 connected to the pressure stabilizing structure 2 for introducing gas from the pressure stabilizing structure 2 and liquefying the gas; and a gas input structure 6 whose input end is connected to the liquefaction device 5 and whose output end is connected to the pressure stabilizing structure 2 for introducing gas from the liquefaction device 5 into the pressure stabilizing structure 2.

[0047] When the external temperature rises, the light hydrocarbon gas present in the above-mentioned atmospheric pressure storage tank 1 generates a large amount of light hydrocarbon gas, which is transported by the gas collection structure 10 to the pipeline and enters the pressure stabilizing structure 2. A portion of the light hydrocarbon gas is converted into liquid in the pressure stabilizing structure 2 and flows into the liquid storage structure 3. When the gas in the pressure stabilizing structure 2 reaches the limit, the regulating structure 4 can start the liquefaction device 5, so that the gas in the pressure stabilizing structure 2 enters the liquefaction device 5, and then the liquefaction device 5 liquefies and stores the light hydrocarbon gas for the purpose of collecting the light hydrocarbon gas.

[0048] When the external temperature of atmospheric pressure storage tank 1 decreases, the amount of light hydrocarbon gas present in it decreases, causing the gas in pressure stabilizing structure 2 to be drawn back. As the amount of gas in pressure stabilizing structure 2 decreases, when the amount of gas reduced in pressure stabilizing structure 2 reaches its limit, the gas input structure 6 opens, transporting the unliquefied light hydrocarbon gas in liquefaction device 5 to pressure stabilizing structure 2, and then from pressure stabilizing structure 2 to gas collecting structure 10. Finally, gas collecting structure 10 transports the light hydrocarbon gas back to atmospheric pressure storage tank 1 to stabilize the pressure of atmospheric pressure storage tank 1.

[0049] In some embodiments, such as Figure 4 As shown, the gas collection structure 10 includes a floating plate 11, a sealing airbag 14, a three-way pipe 15, and a telescopic pipe 16. The floating plate 11 has an annular protrusion 13 at the edge of its end face away from the oil surface. The side wall of the floating plate 11 has a through hole 12 along the diameter direction of the floating plate 11. The sealing airbag 14 is an annular elastic airbag with an opening facing the oil surface and connected to the edge protrusion of the floating plate 11. The other side of the sealing airbag 14 abuts against the inner side wall of the atmospheric pressure storage tank 1. The telescopic pipe 16 is connected to the three-way pipe 15. The three-way pipe 15 is connected to the surface of the floating plate 11 and to the through hole 12.

[0050] The aforementioned floating plate 11 is in contact with the oil surface of the atmospheric pressure storage tank 1 and floats on the oil surface, allowing the floating plate 11 to float up and down with the oil surface. When light hydrocarbon gas is generated in the atmospheric pressure storage tank 1, the generated light hydrocarbon gas enters the interior of the sealing airbag 14 through the opening side of the sealing airbag 14, or enters the interior of the sealing airbag 14 through the gap between the floating plate 11 and the oil surface. This allows the sealing airbag 14 to be in an elastically expanded state, blocking the light hydrocarbon gas from entering the space above the atmospheric pressure storage tank 1 and collecting the light hydrocarbon gas. Then, the light hydrocarbon gas enters the three-way pipe 15 through the through hole 12 on the side wall of the floating plate 11, and is then transported to the pressure stabilizing structure 2 through the three-way pipe 15.

[0051] In some embodiments, such as Figure 1 and Figure 2As shown, the pressure stabilizing structure 2 includes a gas storage tank 21, a top cover 25, and a pressure cylinder 24. The gas storage tank 21 is connected to the atmospheric pressure storage tank 1 via a pipeline, communicates with the liquid storage structure 3, is connected to the liquefaction device 5, and is connected to the gas input structure 6. One end of the gas storage tank 21 is open. An annular groove 23 is provided on the end face of the open end of the gas storage tank 21, surrounding the opening of the gas storage tank 21 and concentrically positioned with the end face of the gas storage tank 21. The end face of the annular groove 23 and the end face of the gas storage tank 21 are on the same horizontal line, and the annular groove 23 contains a sealing liquid 22. The top cover 25 is fixedly connected to one end face of the pressure cylinder 24, which is placed in the annular groove 23, with the other end face of the pressure cylinder 24 immersed in the sealing liquid 22.

[0052] The side wall of the aforementioned gas storage tank 21 is connected to the atmospheric pressure storage tank 1 via a pipeline. Excess light hydrocarbon gas in the atmospheric pressure storage tank 1 enters the gas storage tank 21 through this pipeline. As the light hydrocarbon gas flows, its temperature decreases, causing the light hydrocarbon gas in the gas storage tank 21 to separate the water vapor and other liquids it carries. The water vapor and other liquids flow into the liquid storage structure 3 connected to the gas storage tank 21. As the amount of light hydrocarbon gas in the gas storage tank 21 gradually increases, when it exceeds the original capacity of the gas storage tank 21, the gas will push up the top cover 25, and the pressure cylinder 24 will rise. The sealing liquid 22 in the annular groove 23 forms a liquid level difference on the inner and outer sides of the side wall of the pressure cylinder 24 to maintain a constant pressure in the gas storage tank 21.

[0053] Furthermore, when a sudden change in external temperature causes a sharp increase in light hydrocarbon gas in atmospheric pressure storage tank 1, a corresponding increase in light hydrocarbon gas entering storage tank 21 will also occur. When this exceeds the carrying capacity of storage tank 21, the top cover 25 will cause the pressure cylinder 24 to separate from the storage tank, releasing a large amount of light hydrocarbon gas and preventing an explosion.

[0054] Furthermore, by configuring the aforementioned floating roof 11 and other structures, and connecting it to the pressure stabilizing structure 2, a slightly positive pressure can be effectively maintained inside the atmospheric pressure storage tank 1. This eliminates the need to add other inert gases to the atmospheric pressure storage tank 1 for pressure stabilization, improving economic efficiency and reducing the risk of explosions or other accidents within the atmospheric pressure storage tank 1. In some embodiments, such as... Figure 1 and Figure 2 As shown, the liquid storage structure 3 includes a liquid storage tank 31, a first liquid outlet valve 32, and a first liquid level gauge 33. The liquid storage tank 31 is located at the lower end of the gas storage tank 21 and is connected to the gas storage tank 21. The first liquid outlet valve 32 is located at the bottom of the liquid storage tank 31 and is used to discharge the liquid in the liquid storage tank 31. The first liquid level gauge 33 is an L-shaped long tube and is connected to the outer wall of the liquid storage tank 31 to display the amount of liquid in the liquid storage tank 31.

[0055] The light hydrocarbon gas converted into liquid in the gas storage tank 21 flows into the liquid storage tank 31 for collection and storage. Then, the liquid level gauge 33 can be used to observe whether there is an excess of liquid light hydrocarbon gas in the liquid storage tank 31. If there is too much liquid in the liquid storage tank 31, the first liquid outlet valve 32 is opened to discharge it.

[0056] In some embodiments, such as Figure 1 and Figure 2 As shown, the control structure 4 includes a first pulley 41, a second pulley 43, a lifting rope 42, a gravity block 44, and a limiting rod 45. One end of the lifting rope 42 is connected to the top cover 25. The first pulley 41 is located on the side of the top cover 25 away from the pressure cylinder 24. The second pulley 43 is located with its axis parallel to the axis of the first pulley 41 and at the same horizontal plane. The other end of the lifting rope 42 is connected to the gravity block 44. The limiting rod 45 is equipped with a high-position warning plate 452 and a low-position warning plate 454. The high-position warning plate 452 and the low-position warning plate 454 are arranged parallel to each other, and the limiting rod 45 is located on the side parallel to the side wall of the gravity block 44. The gravity block 44 is located between the high-position warning plate 452 and the low-position warning plate 454.

[0057] The aforementioned gravity block 44 is located between the high-position warning plate 452 and the low-position warning plate 454 on the limiting rod 45. When the temperature rises, as more and more gas enters the gas storage tank 21 from the atmospheric pressure storage tank 1, the aforementioned top cover 25 rises, and the lifting rope 42 moves accordingly. Since the other end of the lifting rope 42 is connected to the gravity block 44, and through the first pulley 41 and the second pulley 43, the gravity block 44 drives the lifting rope 42 to move towards the low-position warning plate 454. When there is too much gas in the gas storage tank 21, the gravity block 44 will contact the low-position warning plate 454. When the temperature drops, as the gas in the gas storage tank 21 enters the atmospheric pressure storage tank 1, the top cover 25 descends. Through the first pulley 41 and the second pulley 43, the gravity block 44 drives the lifting rope 42 to move towards the high-position warning plate 452. When there is too little gas in the gas storage tank 21, the gravity block 44 will contact the high-position warning plate 452.

[0058] In some embodiments, such as Figure 2 and Figure 5As shown, the control structure 4 also includes a first position sensor 451, a second position sensor 453, and a controller 455. The first position sensor 451 is mounted on the high-position warning plate 452 and is used to monitor the first position information between the gravity block 44 and the high-position warning plate 452. The second position sensor 453 is mounted on the low-position warning plate 454 and is used to monitor the second position information between the gravity block 44 and the low-position warning plate 454. The controller 455 is electrically connected to the first position sensor 451, the second position sensor 453, the gas input structure 6, and the liquefaction device 5, respectively. It receives the first and second position information monitored by the first and second position sensors 451 and 453, and controls the opening and closing of the gas input structure 6 and the liquefaction device 5 according to the first and second position information. The controller 455 has a preset upper pressure value limit, and controls the operation and stop of the liquefaction device 5 according to the pressure value fed back by the liquefaction device 5.

[0059] Thus, by using the first position sensor 451 and the second position sensor 453, the first position information and the second position information between the gravity block 44 and the high-position warning plate 452 and the low-position warning plate 454 can be monitored in real time. The first position information and the second position information can be transmitted to the controller 455, so that the controller 455 can automatically control the opening and closing of the gas input structure 6 and the liquefaction device 5 based on the received position information, so as to automatically control the input and output of light hydrocarbon gas in the atmospheric pressure storage tank 1.

[0060] The controller 455 is equipped with a first preset threshold based on the positional relationship between the gravity block 44 and the high-position warning plate 452, and a second preset threshold based on the positional relationship between the gravity block 44 and the low-position warning plate 454. When the temperature inside the atmospheric pressure storage tank 1 rises, more and more gas enters the gas storage tank 21 from the atmospheric pressure storage tank 1, causing the top cover 25 to rise and the gravity block 44 to move downward, thereby causing the gravity block 44 to gradually move towards the position of the low-position warning plate 454. When the second position sensor 453 detects that the distance between the gravity block 44 and the low-position warning plate 454 is less than the second preset threshold, the controller 455 controls the liquefaction device 5 to open, so that the gas in the gas storage tank 21 is output. Correspondingly, when the temperature inside the atmospheric pressure storage tank 1 drops, the gas in the gas storage tank 21 flows back to the atmospheric pressure storage tank 1, causing the top cover 25 to move downwards, while the gravity block 44 rises accordingly. This causes the gravity block 44 to gradually move towards the position of the high-level warning plate 452. Thus, when the first position sensor 451 detects that the distance between the gravity block 44 and the high-level warning plate 452 is less than a first preset threshold, the controller 455 controls the gas input structure 6 to open, so as to input gas into the gas storage tank 21 and allow it to flow back into the atmospheric pressure storage tank 1. For example, the first preset threshold and the second preset threshold are both 0.5 cm. When the first position sensor 451 detects that the distance between the gravity block 44 and the high-level warning plate 452 is less than 0.5 cm, the controller 455 controls the gas input structure 6 to operate. When the second position sensor 453 detects that the distance between the gravity block 44 and the low-level warning plate 454 is less than 0.5 cm, the controller 455 controls the liquefaction device 5 to operate.

[0061] In some embodiments, such as Figure 1 , Figure 3 and Figure 5 As shown, the liquefaction device 5 includes a gas output structure 51 and a pressure structure 52. The gas output structure 51 includes an output pipe 511, a gas pump 512, a gas-liquid separation chamber 513, a one-way valve 514, and a first heat sink 515. One end of the output pipe 511 is connected to the gas storage tank 21, and the other end of the output pipe 511 is connected to the pressure structure 52. An air pump 512 is installed on the output pipe 511 and is connected to the output pipe 511. The air pump 512 is used to accelerate the delivery of gas in the output pipe 511. The controller 455 is electrically connected to the air pump 512. A second liquid outlet valve 516 is installed at the bottom of the gas-liquid separation chamber 513. The second liquid outlet valve 516 is used to discharge the liquid in the gas-liquid separation chamber 513. The gas-liquid separation chamber 513 is installed on the output pipe 511 and is connected to the output pipe 511. A one-way valve 514 is installed on the output pipe 511. A first heat sink 515 is wrapped around the output pipe 511 and is installed at one end of the output pipe 511 that is connected to the pressure structure 52.

[0062] When the controller 455 is started, it controls the air pump 512 to draw out excess gas from the gas storage tank 21 through the output pipe 511. The gas then enters the gas-liquid separation chamber 513 through the air pump 512. In the gas-liquid separation chamber 513, due to the pressure difference, some of the light hydrocarbon gas will be converted into liquid. The liquid light hydrocarbon gas remains in the gas-liquid separation chamber 513. When there is too much liquid light hydrocarbon gas in the gas-liquid separation chamber 513, the second liquid outlet valve 516 is opened to discharge the excess liquid light hydrocarbon gas. The remaining light hydrocarbon gas in the gas-liquid separation chamber 513 passes through the output pipe 511 and the one-way valve 514. The one-way valve 514 allows the gas to pass through in one direction to prevent gas backflow. Then the gas flows through the output pipe 511 wrapped by the first heat sink 515. Because the gas temperature is too high, the gas temperature decreases when it flows through the output pipe 511 wrapped by the first heat sink 515, and then flows into the pressure structure 52.

[0063] It should be noted that a valve may also be installed on the output pipe 511 and electrically connected to the controller 455 so that the valve on the output pipe 511 is opened when the air pump 512 is turned on.

[0064] In some embodiments, such as Figure 1 , Figure 3 and Figure 5 As shown, the pressure structure 52 includes a pressure tank 524, a liquid blocking plate 522, a pressure gauge 521, a third liquid outlet valve 525, and a second liquid level gauge 523. The other end of the output pipe 511 is connected to the pressure tank 524. The pressure tank 524 is connected to the gas input structure 6. The liquid blocking plate 522 is provided inside the pressure tank 524. The liquid blocking plate 522 includes an inclined portion 5222 and an inverted V portion 5221. The inclined portion 5222 is provided on the inner wall of the pressure tank 524. The inclined portion 5222 extends from the inner wall of the pressure tank 524 toward the central axis of the pressure tank 524 and is inclined toward the bottom of the pressure tank 524. The inverted V portion 5221 is provided on the side of the inclined portion 5222 near the bottom of the pressure tank 524. The inclined portion 5222 and the inverted V portion 5221 are fixedly connected and have a gap. Pressure gauge 521 is installed on the outer wall of pressure tank 524 and is electrically connected to controller 455. Third discharge valve 525 is installed at the bottom of pressure tank 524 and is used to discharge liquid from pressure tank 524. Second level gauge 523 is an L-shaped long tube and is installed on the outer wall of pressure tank 524 to display the amount of liquid in pressure tank 524.

[0065] The pressure tank 524 is under high pressure. When light hydrocarbon gas enters, due to the reduced temperature and high pressure, most of the light hydrocarbon gas will be converted into liquid. The amount of liquid light hydrocarbon gas in the pressure tank 524 can be observed through the second level gauge 523. When too much liquid light hydrocarbon gas is stored in the pressure tank 524, the third outlet valve 525 is opened to discharge the excess liquid light hydrocarbon gas. The pressure gauge 521 displays the pressure inside the pressure tank 524 and provides real-time feedback on the pressure value of the pressure tank 524. The controller 45... 5. The upper limit of the pressure value of the pressure tank 524 is set accordingly. The air pump 512 is opened or closed according to the pressure value fed back by the pressure gauge 521. Light hydrocarbon gas can enter the upper part of the pressure tank 524 through the gap between the inclined part 5222 and the inverted V part 5221 of the liquid blocking plate 522. The inclined part 5222 of the liquid blocking plate 522 blocks the liquid light hydrocarbon gas from entering the upper part of the pressure tank 524. The liquid light hydrocarbon gas flows through the side of the inclined part 5222 near the side wall of the pressure tank 524 to the inverted V part 5221, and then flows down at both ends of the inverted V part 5221.

[0066] In some embodiments, such as Figure 1 , Figure 3 and Figure 5 As shown, multiple liquefaction devices 5 are arranged sequentially. One end of the output pipe 511 in the first liquefaction device 5 is connected to the gas storage tank 21, and the other end is connected to the pressure tank 524 in the first liquefaction device 5. The two pressure tanks 524 in two adjacent liquefaction devices 5 are connected to each other through the output pipe 511. The top of the pressure tank 524 at the end is provided with a gas outlet valve 526, and the pressure tank 524 adjacent to the end pressure tank 524 is connected to the input end of the gas input structure 6.

[0067] All the air pumps 512 and pressure gauges 521 in the aforementioned liquefaction devices 5 are electrically connected to the controller 455. When the gas in the previous pressure tank 524 increases, causing the pressure to rise, the pressure gauge 521 connected to the previous pressure tank 524 reaches the upper limit of the pressure value set by the controller 455. The controller 455 then controls the air pump 512 in the next liquefaction device 5 to open, and the unliquefied gas in the previous pressure tank 524 enters the next pressure tank 524 through the output pipe 511. Since it contains a variety of light hydrocarbon gases, each of which has a different critical pressure value for liquefaction, the pressure in the pressure tanks 524 of the multiple liquefaction devices 5 increases sequentially, with the pressure in the end pressure tank 524 being the highest. In this way, the liquefaction of most of the light hydrocarbon gases can be achieved by passing through pressure tanks 524 with different pressures. When the amount of unliquefied light hydrocarbon gas entering the end pressure tank increases, the pressure gauge 521 in the end pressure tank 524 increases to the upper limit of the pressure value preset by the controller 455. The controller 455 then controls the outlet valve 526 on the end pressure tank 524 to open to release gas and relieve pressure. When the external temperature of the atmospheric pressure storage tank 1 decreases, the amount of light hydrocarbon gas present in it decreases, causing the gas in the pressure stabilizing structure 2 to be drawn back. As the amount of gas in the pressure stabilizing structure 2 decreases, when the amount of gas in the pressure stabilizing structure 2 reaches its limit, the light hydrocarbon gas in the pressure tank 524 adjacent to the end pressure tank 524 in the liquefaction device 5 is transported to the gas storage tank 21 through the gas input structure 6. In this way, most of the light hydrocarbon gas is collected in the pressure tank 524 before the end pressure tank 524, so that most of the gas drawn back into the gas storage tank 21 is non-liquefiable light hydrocarbon gas.

[0068] In some embodiments, such as Figure 1 , Figure 3 and Figure 5 As shown, the gas input structure 6 includes an input pipe 62, a second heat sink 61, and an input valve 63. The input end of the input pipe 62 is connected to the pressure tank 524 adjacent to the end pressure tank 524, and the output end of the input pipe 62 is connected to the gas storage tank 21. The second heat sink 61 is wrapped around the input pipe 62 and is located at the end of the input pipe 62 that is connected to the pressure tank 524. The input valve 63 is located on the input pipe 62 and is used to open or close the input pipe 62. The controller 455 is electrically connected to the input valve 63.

[0069] When the aforementioned gravity block 44 comes into contact with the high-level warning plate 452, the controller 455 starts and controls the aforementioned input valve 63 to open. In this state, the light hydrocarbon gas enters the input pipe 62 from the pressure tank 524. First, the light hydrocarbon gas is cooled by passing through the input pipe 62 wrapped by the second heat sink 61. Then, it enters the gas storage tank 21 through the input valve 63, and the gas storage tank 21 then transports the light hydrocarbon gas to the atmospheric pressure storage tank 1.

[0070] In summary, when the external temperature of the atmospheric pressure storage tank 1 rises, the light hydrocarbon gas enters the floating roof 11 through-hole 12 via the sealed gas bladder 14, then enters the three-way pipe 15, subsequently enters the telescopic pipe 16, and finally enters the gas storage tank 21. Due to the pressure difference between the gas storage tank 21 and the atmospheric pressure storage tank 1, a portion of the light hydrocarbon gas will be converted into liquid light hydrocarbon gas after entering the gas storage tank 21. The liquid light hydrocarbon gas flows into the liquid storage tank 31 connected to the gas storage tank 21. The presence of excess liquid light hydrocarbon gas in the liquid storage tank 31 can then be observed through the first liquid level gauge 33. If there is too much liquid in tank 31, the first liquid outlet valve 32 will be opened to discharge it. As more and more light hydrocarbon gas enters the gas storage tank 21, when it exceeds the capacity of the gas storage tank 21, the top cover 25 will be lifted by the light hydrocarbon gas. The pressure cylinder 24 connected to the top cover 25 will be lifted accordingly. The sealing liquid 22 in the annular groove 23 will form a liquid level difference between the inside and outside of the side wall of the pressure cylinder 24, keeping the pressure in the gas storage tank 21 constant. One end of the lifting rope 42 is connected to the top cover 25. The lifting rope 42 moves through the first pulley 41 and the second pulley 43 to the other end connected to the gravity block 44.

[0071] When the gravity block 44 contacts the low-position warning plate 454, the second position information fed back by the second position sensor 453 reaches the second preset threshold. The controller 455 controls the air pump 512 to open, and the light hydrocarbon gas in the gas storage tank 21 enters the output pipe 511. The light hydrocarbon gas passes through the air pump 512 and enters the gas-liquid separation chamber 513. A portion of the light hydrocarbon gas is converted into liquid and remains in the gas-liquid separation chamber 513. When there is too much liquid light hydrocarbon gas in the gas-liquid separation chamber 513, the second liquid outlet valve 516 is opened to discharge the liquid. The remaining gas enters the output pipe 511, which is wrapped by the first heat sink 515, through the one-way valve 514. This one-way valve 514 can prevent Light hydrocarbon gas is refluxed, and the first heat sink 515 cools the passing light hydrocarbon gas. The cooled light hydrocarbon gas then enters the pressure tank 524, where it is converted into liquid light hydrocarbon gas under high pressure and collected and stored. The amount of liquid light hydrocarbon gas in the pressure tank 524 can be observed by the second liquid level gauge 523. If there is too much liquid in the pressure tank 524, the third liquid outlet valve 525 is opened to discharge it. The pressure gauge 521 displays the pressure in the pressure tank 524, and the pressure in the pressure tank 524 is adjusted accordingly. When there is too much light hydrocarbon gas in the end pressure tank 524, the gas outlet valve 526 is opened to discharge the gas.

[0072] When the external temperature of atmospheric pressure storage tank 1 decreases, light hydrocarbon gas will enter atmospheric pressure storage tank 1 through the pipeline of storage tank 21. As the amount of light hydrocarbon gas in storage tank 21 decreases, the top cover 25 and pressure cylinder 24 descend. Due to the action of lifting rope 42, first slider and second slider, gravity block 44 rises. When gravity block 44 contacts high-level warning plate 452, the first position information fed back by first position sensor 451 reaches the first preset threshold. Controller 455 controls input valve 63 to open. At this time, the pressure in pressure tank 524 decreases, and liquid light hydrocarbon gas is converted. In a gaseous state, the gas rises from the bottom of the pressure tank 524 adjacent to the end, passes through the liquid blocking plate 522 and enters the area above the pressure tank 524, and then enters the input pipe 62. The liquid blocking plate 522 can prevent incompletely vaporized light hydrocarbon gas from entering the area above the pressure tank. The light hydrocarbon gas entering the output pipe 511 first passes through the input pipe 62, which is wrapped by the second heat sink 61, to cool the light hydrocarbon gas. Then it passes through the input valve 63 and enters the gas storage tank 21 through the input pipe 62. The light hydrocarbon gas enters the atmospheric pressure storage tank 1 through the pipeline in the gas storage tank 21 connected to the atmospheric pressure storage tank 1.

[0073] This system can liquefy, collect, and store light hydrocarbon gases generated in atmospheric pressure storage tank 1 due to environmental climate change through low-temperature pressurization, forming an effective resource recycling and utilization. It can also effectively prevent light hydrocarbon gases from entering the atmosphere and causing environmental pollution. Furthermore, this system performs real-time electronic monitoring, which improves the safety and stability of atmospheric pressure storage tank 1.

[0074] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0075] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0076] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A system for staged recovery of light hydrocarbons, for installation on an atmospheric pressure storage tank (1), characterized in that, include: A gas collection structure (10) is provided inside the atmospheric pressure storage tank (1) to collect light hydrocarbon gas in the atmospheric pressure storage tank (1) and transport it. A pressure stabilizing structure (2) is connected to the atmospheric pressure storage tank (1) through a pipeline, and is used to introduce gas from the atmospheric pressure storage tank (1) and perform gas-liquid separation. Liquid storage structure (3), which is connected to the pressure stabilizing structure (2) and is used to store the liquid separated in the pressure stabilizing structure (2); A control structure (4) is provided on the pressure stabilizing structure (2) for signaling the pressure inside the pressure stabilizing structure (2) via gas. A liquefaction device (5) is connected to the pressure stabilizing structure (2) and is used to introduce gas into the pressure stabilizing structure (2) and liquefy the gas. Gas input structure (6), the input end of the gas input structure (6) is connected to the liquefaction device (5), and the output end of the gas input structure (6) is connected to the pressure stabilizing structure (2), for introducing the gas from the liquefaction device (5) into the pressure stabilizing structure (2); The pressure stabilizing structure (2) includes a gas storage tank (21), a top cover (25), and a pressure cylinder (24). The gas storage tank (21) is connected to the atmospheric pressure storage tank (1) through a pipeline. The gas storage tank (21) is connected to the liquid storage structure (3). The gas storage tank (21) is connected to the liquefaction device (5). The gas storage tank (21) is connected to the gas input structure (6). One end of the gas storage tank (21) is open. An annular groove (23) is provided on the end face of the open end of the gas storage tank (21). The annular groove (23) surrounds the opening of the gas storage tank (21) and is concentric with the end face of the gas storage tank (21). The end face of the annular groove (23) and the end face of the gas storage tank (21) are on the same horizontal line. The annular groove (23) contains sealing liquid (22). The top cover (25) is fixedly connected to one end face of the pressure cylinder (24), the pressure cylinder (24) is placed in the annular groove (23), and the other end face of the pressure cylinder (24) is immersed in the sealing liquid (22).

2. The system for staged recovery of light hydrocarbons according to claim 1, characterized in that, The gas collection structure (10) includes a floating plate (11), a sealing airbag (14), a three-way pipe (15), and a telescopic pipe (16). The floating plate (11) floats on the oil surface inside the atmospheric pressure storage tank (1). The diameter of the floating plate (11) is smaller than the inner diameter of the atmospheric pressure storage tank (1). An annular protrusion (13) is provided at the edge of the surface of the floating plate (11). A through hole (12) is provided on the side wall of the floating plate (11) along the diameter direction of the floating plate (11). The sealing airbag (14) is an annular elastic airbag, and the sealing airbag (14) opens towards the oil surface. One side of the sealing airbag (14) is connected to the annular protrusion (13), and the other side of the sealing airbag (14) abuts against the inner side wall of the atmospheric pressure storage tank (1). The three-way pipe (15) is provided on the surface of the floating plate (11). The telescopic pipe (16) is connected to the upper interface of the three-way pipe (15), and the two ends of the three-way pipe (15) are connected to the through hole (12).

3. The system for staged recovery of light hydrocarbons according to claim 1, characterized in that, The liquid storage structure (3) includes a liquid storage tank (31), a first liquid outlet valve (32) and a first liquid level gauge (33). The liquid storage tank (31) is located at the lower end of the gas storage tank (21) and is connected to the gas storage tank (21). The first liquid outlet valve (32) is located at the bottom end of the liquid storage tank (31) and is used to discharge the liquid in the liquid storage tank (31). The first liquid level gauge (33) is an L-shaped long tube and is connected to the outer wall of the liquid storage tank (31) and is used to display the amount of liquid in the liquid storage tank (31).

4. The system for staged recovery of light hydrocarbons according to claim 1, characterized in that, The control structure (4) includes a first pulley (41), a second pulley (43), a lifting rope (42), a gravity block (44), and a limiting rod (45). One end of the lifting rope (42) is connected to the top cover (25), the first pulley (41) is located on the side of the top cover (25) away from the pressure cylinder (24), the second pulley (43) is located on the same horizontal plane as the axis of the first pulley (41), and the other end of the lifting rope (42) is connected to the gravity block (44). The limiting rod (45) is provided with a high-position warning plate (452) and a low-position warning plate (454). The high-position warning plate (452) and the low-position warning plate (454) are arranged in parallel. The limiting rod (45) is arranged on the side parallel to the side wall of the gravity block (44). The gravity block (44) is arranged between the high-position warning plate (452) and the low-position warning plate (454).

5. A system for staged recovery of light hydrocarbons according to claim 4, characterized in that, The control structure (4) also includes a first position sensor (451), a second position sensor (453), and a controller (455). The first position sensor (451) is disposed on the high-position warning plate (452) and is used to monitor the first position information between the gravity block (44) and the high-position warning plate (452); The second position sensor (453) is disposed on the low-position warning plate (454) and is used to monitor the second position information between the gravity block (44) and the low-position warning plate (454); The controller (455) is electrically connected to the first position sensor (451), the second position sensor (453), the gas input structure (6), and the liquefaction device (5), respectively. It is used to receive first position information and second position information monitored by the first position sensor (451) and the second position sensor (453), and to control the opening and closing of the gas input structure (6) and the operation of the liquefaction device (5) according to the first position information and the second position information.

6. A system for staged recovery of light hydrocarbons according to claim 5, characterized in that, The liquefaction device (5) includes a gas output structure (51) and a pressure structure (52). The gas output structure (51) includes an output pipe (511), a gas pump (512), a gas-liquid separation chamber (513), a one-way valve (514), and a first heat sink (515). One end of the output pipe (511) is connected to the gas storage tank (21), and the other end of the output pipe (511) is connected to the pressure structure (52). The air pump (512) is installed on the output pipe (511) and is connected to the output pipe (511). The air pump (512) is used to accelerate the delivery of gas in the output pipe (511). The controller (455) is electrically connected to the air pump (512). A second liquid outlet valve (516) is installed at the bottom of the gas-liquid separation chamber (513). The second liquid outlet valve (516) is used to discharge the liquid in the gas-liquid separation chamber (513). The gas-liquid separation chamber (513) is installed on the output pipe (511) and is connected to the output pipe (511). The one-way valve (514) is installed on the output pipe (511). The first heat sink (515) is wrapped around the output pipe (511). The first heat sink (515) is installed at one end of the output pipe (511) connected to the pressure structure (52).

7. The system for staged recovery of light hydrocarbons according to claim 6, characterized in that, The pressure structure (52) includes a pressure tank (524), a liquid-blocking plate (522), a pressure gauge (521), a third outlet valve (525), and a second level gauge (523). The other end of the output pipe (511) is connected to the pressure tank (524). The pressure tank (524) is connected to the gas input structure (6). The liquid-blocking plate (522) is installed inside the pressure tank (524). The liquid-blocking plate (522) includes an inclined portion (5222) and an inverted V portion (5221). The inclined portion (5222) is disposed on the inner wall of the pressure tank (524). The inclined portion (5222) extends from the inner wall of the pressure tank (524) toward the central axis of the pressure tank (524) and is inclined toward the bottom of the pressure tank (524). The inverted V portion (5221) is disposed on the side of the inclined portion (5222) near the bottom of the pressure tank (524). The inclined portion (5222) and the inverted V portion (5221) are fixedly connected and have a gap. The pressure gauge (521) is installed on the outer wall of the pressure tank (524) and is electrically connected to the controller (455). The third discharge valve (525) is installed at the bottom of the pressure tank (524) and is used to discharge the liquid in the pressure tank (524). The second level gauge (523) is an L-shaped long tube and is installed on the outer wall of the pressure tank (524) to display the amount of liquid in the pressure tank (524).

8. A system for staged recovery of light hydrocarbons according to claim 7, characterized in that, The liquefaction device (5) is arranged in sequence in multiple ways. One end of the output pipe (511) of the first liquefaction device (5) is connected to the gas storage tank (21), and the other end is connected to the pressure tank (524) of the first liquefaction device (5). The two pressure tanks (524) of two adjacent liquefaction devices (5) are connected to each other through the output pipe (511). The pressure tank (524) at the end is provided with an exhaust valve (526) at its top. The pressure tank (524) adjacent to the end pressure tank (524) is connected to the input end of the gas input structure (6).

9. A system for staged recovery of light hydrocarbons according to claim 7, characterized in that, The gas input structure (6) includes an input pipe (62), a second heat sink (61), and an input valve (63). The input end of the input pipe (62) is connected to the pressure tank (524) adjacent to the end of the pressure tank (524). The output end of the input pipe (62) is connected to the gas storage tank (21). The second heat sink (61) is wrapped around the input pipe (62) and is located at one end of the input pipe (62) connected to the pressure tank (524). The input valve (63) is located on the input pipe (62) and is used to open or close the input pipe (62). The controller (455) is electrically connected to the input valve (63).

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